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Celexa (citalopram) and Lexapro (escitalopram) are chemically-analogous medications within the selective-serotonin reuptake inhibitor (SSRI) classification that are regularly prescribed for the management of neuropsychiatric disorders.  Chemically, Celexa contains enantiomers S-citalopram and R-citalopram – whereas Lexapro solely contains S-citalopram (hence its chemical name “es-citalopram”).

The chemical “citalopram” (Celexa) was originally synthesized in 1972 by scientists at the pharmaceutical company Lundbeck whereafter it was released in 1989 for medical use in Denmark.  Celexa eventually received FDA approval in 1998 for the treatment of major depressive disorder in the United States.

Development of “escitalopram” (Lexapro) began in 1997 as a collaboration between pharmaceutical companies Lundbeck (developer of Celexa) and Forest Laboratories.  Lexapro received FDA approval for the treatment of major depressive disorder (MDD) in 2002 and generalized anxiety disorder in 2003 – within the United States.

Celexa (Citalopram) vs. Lexapro (Escitalopram)

Below is a chart in which general attributes of Celexa (citalopram) and Lexapro (escitalopram) are documented.  Reviewing this chart should help in identifying basic similarities and differences between these chemically-similar selective-serotonin reuptake inhibitors (SSRIs).

 CelexaLexapro
IngredientCitalopram hydrobromideEscitalopram oxalate
Drug classificationSSRI (Selective-Serotonin Reuptake Inhibitor)SSRI (Selective-Serotonin Reuptake Inhibitor)
Approved medical usesMajor depressive disorder (MDD).Major depressive disorder (MDD).

Generalized anxiety disorder (GAD).
Off-label usesBody dysmorphic disorder. Dementia-related behavioral disturbances. Diabetic neuropathy. Dysthymia. Generalized anxiety disorder. Hot flashes. Hypersexuality. Obsessive-compulsive disorder (OCD). Panic disorder. Premature ejaculation. Premenstrual dysphoric disorder (PMDD). Social anxiety disorder.Body dysmorphic disorder. Hot flashes. Obsessive-compulsive disorder (OCD). Panic disorder. Premature ejaculation. Premenstrual dysphoric disorder (PMDD). Social anxiety disorder.
Bioavailability~80% (oral)~80% (oral)
FormatsTablet. Oral solution.Tablet. Oral solution.
DosagesTablet: 10 mg, 20 mg, 40 mg

Oral solution: 10 mg/5 mL
Tablet: 5 mg, 10 mg, 20 mg

Oral solution: 5 mg/5 mL
DevelopersLundbeckLundbeck & Forest Laboratories
Legal statusRx (Prescription)-only (U.S.)Rx (Prescription)-only (U.S.)
Mechanism of actionSelective-serotonin reuptake inhibitor.

Interacts with the serotonin transporter (SERT) to prevent reabsorption of serotonin into the presynaptic neuron.

Modestly modulates activation of H1 (histamine) receptors and 5-HT2C receptors.
Selective-serotonin reuptake inhibitor.

Interacts with the serotonin transporter (SERT) to prevent reabsorption of serotonin into the presynaptic neuron.

Modestly agonizes sigma-1 and sigma-2 receptors.
Generic version (?)Yes.Yes.
Half-Life24 to 48 hours (~35 hours)27 to 33 hours
Common side effectsEjaculation disorder. Nausea. Dry mouth. Somnolence. Insomnia. Sweating.Insomnia. Ejaculation disorder. Nausea. Sweating. Fatigue. Somnolence. Decreased libido. Anorgasmia.
Date approved (U.S.)1998 (July)2002 (August)
Duration of effect24 hours24 hours
MetabolismHepatic: CYP2C19. CYP2D6. CYP3A4.Hepatic: CYP2C19. CYP2D6. CYP3A4.
Onset of action4 to 8 weeks (on average)4 to 8 weeks (on average)

Note: The information included within the above chart may be outdated and/or subject to inaccuracies.  Should you have any questions regarding Celexa and/or Lexapro – consult a licensed medical doctor and/or pharmacist.

Celexa vs. Lexapro: What are the general differences?

Although Celexa and Lexapro are similar (in that each contains S-citalopram), they are not identical medications.  General [obvious] differences between Celexa and Lexapro include: release dates; authorized (FDA) medical uses (U.S.); dosing; and pharmacodynamics.  Other suspected differences between Celexa and Lexapro might include: elimination half-life; therapeutic efficacy; incidence of specific side effects; and/or tolerability.

As was mentioned, citalopram (Celexa) was first synthesized in 1972 and approved for medical use in 1998 within the U.S. – whereas escitalopram (Lexapro) was synthesized in 1997 and approved for medical use in 2002 within the U.S.  Celexa is solely approved by the U.S. FDA for the treatment of major depressive disorder (MDD) – whereas Lexapro is approved by the U.S. FDA for the treatment of major depressive disorder (MDD) and generalized anxiety disorder (GAD).

Though Celexa and Lexapro are manufactured in the same number of dosing increments (3 for tablet; 1 for oral solution), Celexa dosages are double (in milligrams) the corresponding dosages of Lexapro.  The reason Celexa dosages (in milligrams) are 2-fold the corresponding dosages of Lexapro is because Celexa contains a racemic blend of 50% S-citalopram and 50% R-citalopram – whereas Lexapro contains 100% S-citalopram.

It is thought that the S-citalopram isomer modulates neurochemistry in ways that yield therapeutically-relevant effects – and that R-citalopram isomer fails to modulate neurochemistry therapeutically-relevant ways.  Since Celexa is diluted with an equal mixture of S-citalopram and R-citalopram, and Lexapro is concentrated with the therapeutically-relevant S-citalopram – the dosage increments of Celexa end up double (in milligrams) the corresponding dosage increments of Lexapro.

Moreover, while the principal mechanism of action for Celexa and Lexapro is identical, the medications exhibit subtle differences in pharmacodynamics.  Celexa exhibits less selectivity than Lexapro in that Celexa interacts with: H1 histamine receptors, 5-HT2C receptors; alpha-1 adrenergic receptors; M1 muscarinic receptors; and the NET (norepinephrine transporter).

Lexapro exhibits the most selective action of all serotonergic antidepressants in that it does not significantly interact with many neurochemical targets beyond the serotonin transporter (SERT).  The only relevant secondary neurochemical action of Lexapro might involve modulation of sigma receptors (sigma-1 and sigma-2).

Furthermore, although some suspect that there are no significant differences in the respective elimination half-lives of Celexa and Lexapro, studies have reported distinct half-life ranges for each medication.  The elimination half-life of Celexa is estimated to range from 24 to 48 hours (~35-hour average) – and the elimination half-life of Lexapro is estimated to range from 27 to 33 hours.

It’s also necessary to mention that various head-to-head trials and systematic reviews have documented Lexapro as being modestly more effective than Celexa for the treatment of major depressive disorder (MDD).  Lastly, some studies claim that Lexapro is more tolerable and causes fewer side effects than Celexa.

Approved Medical Uses & Off-Label Uses

Celexa and Lexapro are both approved by the Food and Drug Administration (FDA) for the treatment of major depressive disorder (MDD) in the United States.  Though both medications are FDA-approved to treat major depressive disorder, only Lexapro has received an additional FDA-approval to treat generalized anxiety disorder (GAD).

In European countries, Celexa is licensed to treat panic disorder (with or without agoraphobia) – and Lexapro is approved to treat social anxiety disorder (SAD); obsessive-compulsive disorder (OCD); and panic disorder (with or without agoraphobia).  Throughout the United States and Europe, Lexapro is authorized to treat 5 medical conditions – whereas Celexa is authorized to treat 2 medical conditions.

Both Lexapro and Celexa are frequently utilized “off-label” to treat medical conditions for which they haven’t officially been approved.  Documented off-label uses for Celexa include: body dysmorphic disorder; dementia-related behavioral disturbances; diabetic neuropathy; dysthymia; generalized anxiety disorder; hot flashes; hypersexuality; obsessive-compulsive disorder; panic disorder; premature ejaculation; premenstrual dysphoric disorder; and social anxiety disorder.

Documented off-label uses for Lexapro include: body dysmorphic disorder; hot flashes; obsessive-compulsive disorder; panic disorder; premature ejaculation; premenstrual dysphoric disorder; and social anxiety disorder.  Overall, there are no significant differences between Celexa and Lexapro in their respective off-label uses.

The only obvious difference between Celexa and Lexapro in off-label use is that Celexa is prescribed off-label to treat generalized anxiety disorder (GAD), a condition for which Lexapro is FDA-approved.  Moreover, while there might be disparities in the respective usage rates of these medications for specific medical conditions – most clinicians will regard Celexa and Lexapro as interchangeable treatment options.

Cost: What are the prices?

Although most consumers probably don’t consider Celexa (citalopram) and Lexapro (escitalopram) to differ significantly in pricing, Lexapro (escitalopram) tends to be slightly more expensive (on average) than Celexa (citalopram).  The average cost of 30 generic Celexa (citalopram) tablets ranges from $4 to $22, whereas the average cost of 30 generic Lexapro (escitalopram) tablets ranges from $8 to $49 (on average).

Celexa cost

  • Citalopram tablets (generic): $4 to $22 (30 tablets)
  • Citalopram oral solution (generic): $55 to $67 (240 mL of 10 mg/5 mL)
  • Celexa tablets (brand name): $267 to $309 (30 tablets)

Lexapro cost

  • Escitalopram tablets (generic): $8 to $49 (30 tablets)
  • Escitalopram oral solution (generic): $67 to $116 (240 mL of 5 mg/5mL)
  • Lexapro tablets (brand name): $306 to $358 (30 tablets)
  • Lexapro oral solution (brand name): $500 to $538 (240 mL of 5 mg/5mL)

Furthermore, though the pricing of 30 generic Lexapro (escitalopram) tablets might exceed the pricing of 30 generic Celexa (citalopram) tablets at select pharmacies, a majority of pharmacies retail 30 generic Lexapro (escitalopram) tablets for under $26 – bringing the price range for generic Lexapro (escitalopram) tablets closer to the price range for generic Celexa (citalopram) tablets.

If comparing the cost of generic oral Celexa (citalopram) solution to the cost of generic oral Lexapro (escitalopram) solution, the former is slightly less expensive (on average) than the latter.  A 240 mL bottle of generic oral Celexa (citalopram) solution (containing 10 mg/5 mL) ranges in cost from $55 to $67, whereas a 240 mL bottle of generic oral Lexapro (escitalopram) solution (containing 5 mg/5 mL) ranges in cost from $67 to $116.

On a “per dose” basis, the cost of generic oral Celexa (citalopram) ranges from $1.14 to $1.39, and the cost of generic oral Lexapro (escitalopram) ranges from $1.39 to $2.41.  Although most consumers will utilize generic formats of Celexa (citalopram) and Lexapro (escitalopram) to save themselves money, some individuals regard generics as inferior to brand name formats in terms of efficacy and tolerability.

If comparing the cost of standard “brand name” Celexa tablets to the cost of standard “brand name” Lexapro tablets – the price of the former tends to be slightly lower than that of the latter.  The price for 30 brand name Celexa tablets ranges from $267 to $309 and the price for 30 brand name Lexapro tablets ranges from $306 to $358 – at most pharmacies.

Moreover, while brand name oral Celexa solution is no longer in production, brand name oral Lexapro solution retails for $500 to $538 – at most pharmacies.  In summary, the average cost of Celexa (citalopram) appears modestly lower than the average cost of Lexapro (escitalopram) – regardless of whether generic (tablet or oral solution) or brand name.

Note: The prices documented above for Celexa and Lexapro may be subject to inaccuracies and/or future adjustment.  Understand that pricing of brand name Celexa and Lexapro formats tend to be dose-dependent (in that higher doses cost more, on average, than lower doses).  Also realize that the cost of Celexa and Lexapro might vary substantially among retailing pharmacies.

Efficacy: Is Lexapro more effective than Celexa?

It’s unclear as to whether there are significant (i.e. clinically-relevant) differences in the respective efficacies of Celexa and Lexapro in the treatment of any specific medical condition.  Because major depressive disorder (MDD) is the sole medical condition for which both Celexa and Lexapro are approved, prospective consumers and prescribers of these medications tend to be most concerned with their respective efficacies in the management of major depressive disorder (MDD).

Major depressive disorder (MDD)

Foremost, it is necessary to underscore the fact that both Celexa and Lexapro have proven effective in numerous large-scale, randomized, double-blind, placebo-controlled trials as treatments for major depressive disorder (MDD).  As a result, both Celexa and Lexapro have been granted FDA approval to treat major depressive disorder in the United States.

Although both Celexa (citalopram) and Lexapro (escitalopram) are efficacious treatments for major depressive disorder (MDD), evidence suggests that Lexapro might be modestly more effective than Celexa.  Included below are brief synopses of studies in which the antidepressant efficacies of Celexa and Lexapro were compared and/or discussed.

2018: Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis.

In the most comprehensive systematic review and meta-analysis to date, Cipriani et al. compared the acute efficacies of 21 antidepressant medications (including Celexa and Lexapro).  Data for the review were extracted from 522 randomized controlled trials encompassing 116,477 participants.

In terms of antidepressant efficacy, all 21 antidepressants reviewed were significantly more effective than a placebo comparator.  Reported odds ratios (ORs) in placebo-controlled trials, or probabilities of medications facilitating a significant antidepressant effect (relative to a placebo), were 1.68 for Lexapro versus 1.52 for Celexa.

The aforementioned odds ratios for Lexapro (1.68) and Celexa (1.52) indicate that Lexapro is more likely than Celexa to generate a significant antidepressant effect.  Additionally, a separate portion of the review in which data from head-to-head (comparison) trials were extracted to determine “head-to-head” efficacies of antidepressants – further indicated that Lexapro was more effective than Celexa.

Of all 21 antidepressants in the review, Lexapro ranked 3 out of 21 in head-to-head antidepressant efficacy – whereas Celexa ranked 12 out of 21 in head-to-head antidepressant efficacy.  Based on comparison trial data, Lexapro was referenced as being among the most efficacious antidepressant options, whereas Celexa was not.

This review also noted that Lexapro users exhibited higher response rates and lower dropout rates than Celexa users.  Overall, the findings presented in this comprehensive systematic review by Cipriani et al. support the idea that Lexapro might be more effective than Celexa as an antidepressant.

2012: Citalopram versus other anti-depressive agents for depression.

An earlier review by Cipriani et al. compared the efficacy of Celexa (citalopram) to other antidepressants, including Lexapro (escitalopram), for the treatment of major depressive disorder (MDD).  In this review, researchers extracted data from 37 randomized controlled trials published before February 2012 in which the efficacy of citalopram was directly compared to another antidepressant in “head-to-head” manner.

Results of this review indicated that citalopram (Celexa) was significantly less effective than escitalopram (Lexapro) in generating an acute antidepressant effect.  Although the findings of this review may accurately reflect differences in efficacies between Celexa and Lexapro, researchers reported potential limitations associated with studies utilized in this review including: sponsorship bias and/or publication bias.

Considering the potential biases (sponsorship and/or publication) associated with the studies included in this review, it’s possible that the findings of this review may be inaccurate.  That said, if biases didn’t impact the outcomes of studies included in this review, then Lexapro should be considered a more effective antidepressant than Celexa.

2012: Effectiveness and cost-effectiveness of antidepressants in primary care: a multiple treatment comparison meta-analysis and cost-effectiveness model.

Ramsberg et al. conducted a meta-analysis in which the efficacies of 10 antidepressant medications (including Celexa and Lexapro) were compared.  For the meta-analysis, researchers gathered data from 87 randomized controlled trials encompassing 20,000 patients with moderate-to-severe depression – who were treated over a 1-year span.

With data acquired from these trials, researchers specifically assessed “remission rates” and “quality-of-life” for users of each of the 10 antidepressant medications.  Results indicated that the probabilities of depression remission for Celexa users were “0.38” (all studies) and “0.404” (8-to-12 week studies) – and probabilities of depression remission for Lexapro users were “0.456” (all studies) and “0.471” (8-to-12-week studies).

Based on these data, it’s apparent Lexapro users are more likely to experience remission of depressive symptoms – relative to Celexa users.  Moreover, results of the meta-analysis indicated that Lexapro was the most favorable of all antidepressants in remission probability based on data from “all studies” and “8-to-12 week” studies.

Additionally, results of the meta-analysis revealed that Lexapro was associated with the best quality-of-life at 1-year of treatment – relative to the other 9 antidepressant medications.  Authors noted that Lexapro was superior to all other antidepressants (including Celexa) in: (1) reducing the amount of time spent in depression; (2) improving quality-of-life among patients with depression; and (3) facilitating remission of depressive symptoms.

2012: Clinical efficacy and achievement of a complete remission in depression: increasing interest in treatment with escitalopram.

Favré conducted a literature review in which the antidepressant efficacy of Lexapro was compared to other medications (one of which was Celexa) among adults with major depressive disorder (MDD).  For the review, data were extracted and assessed from studies published within PubMed after 2004.

Favré referenced the meta-analysis by Cipriani et al. (2009) in which Lexapro and Zoloft were discovered to be more effective than 10 other medications (including Celexa) as an acute (8-week) treatment for depression.  Favré also referenced a post-hoc analysis by Kasper et al. (2009) in which multiple 6-month randomized controlled trials documented Lexapro as exhibiting superior efficacy relative to Paxil in the treatment of depression.

Moreover, Favré discussed a pooled analysis by Wade et al. (2009) in which the remission rate for Lexapro (51.7%) significantly exceeded that of pooled comparator antidepressants (45.6%) after 24 weeks.  In sum, this review by Favré supports the idea that Lexapro is more effective than Celexa (plus other SSRIs, SNRIs, mirtazapine, bupropion) in the treatment of depression – regardless of whether used acutely or long-term.

2011: Efficacy of escitalopram compared to citalopram: a meta-analysis.

Montgomery et al. conducted a meta-analysis in which the relative efficacies of Lexapro and Celexa were directly compared in the treatment of major depressive disorder (MDD).  For the meta-analysis, researchers analyzed data from 8 randomized controlled trials and 1 naturalistic trial – involving a total of 2009 adults with major depressive disorder (995 Lexapro users vs. 1014 Celexa users).

This meta-analysis revealed that Lexapro was significantly more effective than Celexa in the treatment of major depressive disorder.  The superior antidepressant efficacy of Lexapro relative to Celexa was evidenced by: (1) greater average MADRS (Montgomery-Asberg Depression Rating Scale) score reductions (~1.7 points) at Week 8 of treatment (based on 6 RCTs); (2) higher responder rates (~8.3%) (based on 8 RCTs); and (3) higher remitter rates (~17.6%) (based on 4 RCTs) – among Lexapro users relative to Celexa users.

Overall odds ratios (Lexapro relative to Celexa) significantly favored Lexapro for response (1.44) and remission (1.86).  Authors concluded that Lexapro is significantly more effective than Celexa in the treatment of depression – and that these findings are clinically-relevant.

2010: Comparison of escitalopram vs. citalopram and venlafaxine in the treatment of major depression in Spain: clinical and economic consequences.

Sicras-Mainar et al. organized a study comparing the efficacies of Lexapro, Celexa, and Effexor – among 965 adult patients diagnosed with a new episode of major depression in Spain between 2003 and 2007.  It was noted that none of the patients with new depressive episodes had taken antidepressants within 6 months prior of receiving: Lexapro, Celexa, or Effexor.

After treatment initiation with Lexapro, Celexa, or Effexor – all patients were followed for at least 18 months.  Of the 965 patients included in this study: 131 received Lexapro; 491 received Celexa; and 343 received Effexor.

Results of the study revealed that Lexapro recipients exhibited higher remission rates (58%) than Celexa recipients (38.3%) and Effexor recipients (32.4%).  This supports the idea that Lexapro might be more efficacious than Celexa in the management of depression.

2010: Is escitalopram really relevantly superior to citalopram in treatment of major depressive disorder? A meta-analysis of head-to-head randomized trials.

Trkulja conducted a meta-analysis of head-to-head randomized trials to evaluate whether there were clinically-relevant differences in the respective efficacies of Lexapro (escitalopram) and Celexa (citalopram) in the treatment of major depressive disorder (MDD).  For the study, Trkulja reviewed data from 7 randomized controlled trials in which the antidepressant efficacies of Celexa and Lexapro were compared.

Results of the meta-analysis suggested that Lexapro was more effective than Celexa in combating depressive symptoms – as evidenced by greater reductions on Montgomery-Asberg Depression Rating Scale (MADRS) scores in Lexapro recipients relative to Celexa recipients.  Despite these findings, 95% confidence intervals associated with: (1) average difference in MADRS score reductions and (2) effect size – were “minimally important” and “small,” respectively.

As a result of low confidence in these findings, authors concluded that there was no evidence to substantiate the idea that Lexapro is clinically superior over Celexa in the treatment of major depressive disorder (MDD).  However, there were limited [albeit inconclusive] data indicating that Lexapro might be more effective than Celexa in persons with severe depression (characterized by MADRS scores of 30 or above).

2009: Comparative efficacy and acceptability of 12 new-generation antidepressants: a multiple-treatments meta-analysis.

A multiple-treatments meta-analysis by Cipriani et al. evaluated the efficacies of 12 second-generation antidepressant medications in the treatment of major depression.  This meta-analysis incorporated data from 117 randomized controlled trials (1991 through 2007) involving 25,928 adults with unipolar major depression who received therapeutically-relevant doses of antidepressants.

The 12 second-generation antidepressants included in this meta-analysis were: bupropion, citalopram, duloxetine, escitalopram, fluoxetine, fluvoxamine, milnacipran, mirtazapine, paroxetine, reboxetine, sertraline, and venlafaxine.  Results of this meta-analysis indicated that escitalopram (Lexapro) is one of the most effective antidepressant medications (alongside mirtazapine, venlafaxine, and sertraline).

Cumulative probabilities of being included within the top 4 most effective antidepressants (of the 12 medications compared) were 23.7% for Lexapro – and 3.4% for Celexa.  Based on these findings presented by Cipriani et al., Lexapro appears more effective than Celexa in the treatment of unipolar major depression.

2007: Efficacy and tolerability of escitalopram versus citalopram in major depressive disorder: a 6-week, multicenter, prospective, randomized, double-blind, active-controlled study in adult outpatients.

Yevtushenko et al. conducted a 6-week randomized, double-blind, active-controlled trial directly comparing the efficacies of Lexapro and Celexa.  In the trial, 330 adults with major depressive disorder (MADRS scores of at least 25) were assigned at random to receive either: 10 mg/day Lexapro (108 patients); 10 mg/day Celexa (106 patients); or 20 mg/day Celexa (108 patients).

Data from 322 of the original 330 participants were included in the final assessment.  At study endpoint (after 6 weeks of treatment), recipients of Lexapro (10 mg/day) exhibited significantly greater reductions in depressive symptoms than recipients of Celexa (10 mg/day or 20 mg/day).

Greater reductions in depressive symptoms among Lexapro recipients were evidenced by substantially larger changes in MADRS and CGI scores from baseline – relative to Celexa recipients.  It was further noted that Lexapro recipients exhibited significantly higher response and remission rates than Celexa recipients.

Based on the results of this study, researchers concluded that Lexapro (10 mg/day) appears more effective than Celexa (10 mg/day OR 20 mg/day) for the treatment of major depressive disorder in adult outpatients.  Though there are limitations associated with this study such as: (1) uneven dosing comparisons (10 mg Lexapro vs. 10 mg Celexa); and (2) inflexible, fixed-dosing assignments – results suggest that Lexapro is more effective than Celexa in the treatment of major depression.

2005: Prospective, multicentre, randomized, double-blind study of the efficacy of escitalopram versus citalopram in outpatient treatment of major depressive disorder.

Moore et al. conducted an 8-week randomized, double-blind, clinical trial to compare the effectiveness of fixed-dose Lexapro (20 mg/day) to that of fixed-dose Celexa (40 mg/day) – among 280 patients with major depressive disorder.  Of the 280 participants, 138 received Lexapro (20 mg/day) and 142 received Celexa (40 mg/day).

Results of the trial indicated that Lexapro (20 mg/day) was significantly more effective than Celexa (40 mg/day) in reducing symptoms of major depressive disorder – as evidenced by significantly greater reductions in Montgomery-Asberg Depression Rating Scale (MADRS) scores from baseline among Lexapro recipients relative to Celexa recipients.  Moreover, a greater percentage of Lexapro recipients (76.1%) responded to treatment than Celexa recipients (61.3%).

Respective rates of remission were 56.1% for Lexapro recipients and 43.6% for Celexa recipients.  This randomized controlled trial supports the idea that Lexapro is superior over Celexa in antidepressant efficacy.

2005: Efficacy and safety of second-generation antidepressants in the treatment of major depressive disorder.

Hansen et al. conducted a review to evaluate the head-to-head efficacies of second-generation antidepressants (including Lexapro and Celexa) in the management of major depressive disorder.  Researchers extracted data from 46 head-to-head randomized controlled trials encompassing 11,553 patients (published between 1980 and 2005) in which the effectiveness of one second-generation antidepressant was directly compared to that of another.

If considering the evidence from these trials that was classified as “fair-to-good” quality, there were minimal differences in the respective efficacies of second-generation antidepressants.  In 88% of comparison studies, zero significant differences were observed in any outcome measures at study endpoint.  Overall, this study does not support the idea that Lexapro is significantly more effective than Celexa in the management of major depressive disorder.

2004: Escitalopram is more effective than citalopram for the treatment of severe major depressive disorder.

Azorin et al. conducted a review to determine whether Lexapro was more effective than Celexa in the treatment of severe depression.  For this review, researchers pooled data from 3 different clinical trials with similar designs, inclusion/exclusion criteria, endpoints, and assessment schedules – encompassing 506 patients with severe depression.

Of the 506 patients with severe depression in these trials: 169 received Lexapro; 171 received Celexa; and 166 received a placebo.  Results indicated that Lexapro recipients experienced significantly greater reductions in MADRS total scores from baseline (17.3 points) relative to Celexa recipients (13.8 points) – as early as the first week of treatment.

Additionally, Lexapro recipients exhibited significantly higher response rates (56%) than Celexa recipients (41%)and higher remission rates (43% vs. 33%).  Scales such as the HAM-D; CGI-I; and CGI-S also revealed greater improvement in depressive symptoms among Lexapro recipients relative to Celexa recipients.

Researchers concluded that Lexapro is more effective for the management of severe depression than Celexa.  More specifically, Lexapro appears to exert a stronger antidepressant effect than Celexa and exhibits a faster onset of antidepressant action.

2004: Escitalopram Versus Citalopram and Sertraline: A Double-Blind Controlled, Multi-centric Trial in Indian Patients with Unipolar Major Depression.

Lalit et al. organized a randomized, double-blind, parallel group, controlled, multi-centric trial to determine the effectiveness of escitalopram (Lexapro) compared to citalopram (Celexa) and sertraline (Zoloft) in the management of major depressive disorder (MDD).  A total of 214 outpatients with ongoing/newly-diagnosed major depressive episodes (HAM-D scores exceeding 18) participated in this trial.

The 214 outpatients were randomly assigned to receive either: 10-20 mg/day Lexapro (69 patients); 20-40 mg/day Celexa (74 patients); or 50-150 mg/day Zoloft (71 patients) – for a 4-week duration with dosage adjustments after the first 2 weeks (if necessary).  Response rates after 2 weeks were: 58% for Lexapro; 49% for Celexa; and 52% for Zoloft – and response rates after 4 weeks were: 90% for Lexapro; 86% for Celexa; and 97% for Zoloft.

Remission rates after 4 weeks of treatment were 74% for Lexapro; 65% for Celexa; and 77% for Zoloft.  Researchers concluded that Lexapro has “potentially superior efficacy” over Celexa and comparable effectiveness to Zoloft in the management of major depressive disorder.

In 11 of the 13 reports summarized above, Lexapro was noted as either superior or potentially-superior to Celexa in the treatment of major depressive disorder (MDD).  Moreover, the most comprehensive systematic review of antidepressant efficacy to date by Cipriani et al. (2018) revealed that Lexapro was superior to Celexa in: (1) odds of generating an antidepressant effect relative to a placebo; and (2) antidepressant efficacy in head-to-head comparison trials.

Additionally, in the review by Cipriani et al., Lexapro was ranked as one of the most effective antidepressant medications – whereas Celexa was not.  Other studies (systematic reviews and head-to-head comparison trials) have documented: (1) higher response rates; (2) higher remission rates; (3) larger magnitude of antidepressant effect; (4) greater quality-of-life; and (5) faster onset of antidepressant action – for Lexapro relative to Celexa.

The superiority of Lexapro over Celexa in the treatment of major depressive disorder (MDD) has been demonstrated in short-term, moderate-term, and long-term trials – and among patients with varying severities of depression (moderate, severe, etc.).  Nevertheless, 2 reviews suggest that Lexapro is not superior over Celexa in the treatment of major depressive disorder.

A review by Hansen et al. (2005) noted that there were no significant differences in the respective efficacies of second-generation antidepressants (including Lexapro and Celexa) in the treatment of major depressive disorder (MDD).  Later, Trkulja (2010) questioned preexisting evidence suggesting that Lexapro was superior in antidepressant efficacy over Celexa.

Trkulja analyzed 7 randomized controlled trials in which Lexapro and Celexa were directly assessed in the treatment of depression.  Though the data extracted by Trkulja revealed that Lexapro was more effective than Celexa in reducing symptoms of depression, the differences between Lexapro and Celexa in MADRS score reductions and antidepressant effect sizes were “minimally important” and “small,” respectively.

For this reason, Trkulja suggested there was no convincing evidence supporting the idea that Lexapro is clinically superior to Celexa in the treatment of major depressive disorder (MDD).  Overall, while most systematic reviews suggest that Lexapro is more effective than Celexa in the treatment of major depressive disorder, these reviews base this suggestion on data from trials that are riddled with limitations.

Limitations of Research Comparing Lexapro and Celexa for Depression (Possibilities)

Included below are potential limitations associated with research in which Lexapro and Celexa are compared in the treatment of major depressive disorder.  Understand that these limitations might explain why Lexapro appears more efficacious than Celexa in head-to-head trials and systematic reviews as a treatment for major depressive disorder.

  • Fixed-dosing: Many of trials comparing Celexa to Lexapro in the treatment of major depressive disorder employed “fixed-dosing” regimens for Celexa at 20 mg/day or 40 mg/day. Although in theory 20 mg/day of Celexa should equal 10 mg/day of Lexapro in its magnitude of antidepressant effect – it’s possible that a greater dosage of Celexa (e.g. 25 mg/day) is needed to deliver the same antidepressant effect as Lexapro at 10 mg/day.  For this reason, it’s possible that fixed-dose trials yielded misleading results due to Lexapro doses being more potent than corresponding Celexa doses to which comparisons were made.
  • Reporting bias: Numerical data for post-baseline depression scales such as the HAM-D and CGI-S are missing in several comparison trials. This increases likelihood of “reporting bias” whereby only data portraying Lexapro as superior over Celexa are reported.  Perhaps the HAM-D and CGI-S did not reveal differences between Lexapro and Celexa in effectiveness and therefore were omitted.
  • Presentation of data: In many comparison trials, data were presented in a manner that prevented reliable extraction (such as for a meta-analysis). It’s possible that this may have been intentional to prevent independent researchers from assessing the results.
  • Publication bias: It’s possible that manufacturers of Lexapro might’ve only published studies in which Lexapro appeared superior to Celexa in the treatment of depression – while discarding studies in which Lexapro wasn’t superior to Celexa in the treatment of depression.
  • Sponsorship bias: A total of 6 of 7 trials in which Lexapro was directly compared to Celexa as an antidepressant were sponsored by the pharmaceutical manufacturer of Lexapro. Additionally, many assessments in these trials were authored/co-authored by employees of the pharmaceutical company.
  • Variability measures: No variability measures were reported in these comparisons of Celexa and Lexapro. This may have been done deliberately to increase likelihood that Celexa would appear less efficacious than Lexapro in the treatment of major depressive disorder.

Note: There may be additional limitations associated with studies comparing the antidepressant efficacy of Celexa to that of Lexapro.

In 7 head-to-head trials comparing Celexa and Lexapro, Lexapro was reported as being “significantly more effective” in the treatment of major depressive disorder.  However, 6 out of 7 head-to-head trials were funded by Lundbeck/Forest Laboratories (manufacturers of Lexapro) who, at the time, had financial incentive to showcase the superior efficacy of Lexapro.

Furthermore, results of these trials were authored/co-authored by persons employed at Lundbeck/Forest Laboratories.  In the only trial that was not funded by Lundbeck/Forest Laboratories, no differences in the antidepressant efficacies of Lexapro and Celexa were found.

Verdict: Lexapro might be superior to Celexa for major depressive disorder (MDD)

Even considering the aforementioned limitations associated with the head-to-head comparison trials of Celexa and Lexapro, there are additional data indicating that Lexapro may be superior over Celexa in the treatment of major depressive disorder.  For example, Cipriani et al. (2018) analyzed the efficacies of Celexa and Lexapro in placebo-controlled trials and differences were discovered.

The odds ratio of deriving a significant antidepressant response with Celexa relative to a placebo was 1.52 – and the odds ratio of deriving a significant antidepressant response with Lexapro relative to a placebo was 1.68.  The higher odds ratio for Lexapro (1.68) relative to Celexa (1.52) indicates that Lexapro might be more effective than Celexa in the treatment of major depressive disorder.

Moreover, an independent review by Montgomery and Möller (2009) reported clinically-relevant differences in responder rates between Lexapro (74%) and pooled-comparator antidepressants (63%).  This suggested that Lexapro might be superior in antidepressant efficacy to other medications (including Celexa).

If considering the respective pharmacodynamics of Celexa and Lexapro, it’s reasonable to suspect that Lexapro could prove slightly more effective than Celexa in the treatment of major depressive disorder.  Lexapro contains 100% S-citalopram which selectively inhibits the reuptake of serotonin, whereas Celexa contains 50% R-citalopram which has been suggested to negate the magnitude of antidepressant effect facilitated by 50% S-citalopram.

In the event that R-citalopram is negligibly or modestly reducing the antidepressant actions of S-citalopram, this might explain why Lexapro appears more effective than Celexa in the treatment of depressive disorders.  Lastly, it’s necessary to underscore the fact that zero studies suggest that Celexa is more effective than Lexapro in the treatment of major depressive disorder.

Everything considered (e.g. odds ratios in placebo-controlled trials; outcomes of head-to-head trials; respective pharmacodynamics of each medication; no documented superiority of Celexa over Lexapro), it’s reasonable to suggest that Lexapro might be more effective than Celexa in the treatment of major depressive disorder.  On the basis that Lexapro might be more effective than Celexa in the treatment of major depressive disorder – it’s probably worth trying Lexapro before and/or or instead of Celexa.

Generalized anxiety disorder (GAD)

Because Lexapro (escitalopram) is FDA-approved for the treatment of generalized anxiety disorder (GAD) but Celexa (citalopram) is not, it’s fair to suggest that Lexapro is a medically-superior treatment choice (relative to Celexa) for this condition based on its attainment of FDA-approval.  Nevertheless, while Lexapro can be regarded as a medically-superior treatment choice for generalized anxiety disorder relative to Celexa (due to its FDA-approval), it’s unknown as to whether there are clinically-relevant differences in the respective efficacies of these medications in the treatment of generalized anxiety disorder.

It’s reasonable to speculate that Lundbeck and Forest Laboratories (manufacturers of Lexapro) funded more research in which the efficacy of Lexapro was showcased and/or evaluated in the treatment of generalized anxiety disorder – compared to Celexa.  After all, manufacturers of Lexapro had significantly more incentive to prove its efficacy in the treatment of generalized anxiety disorder – than to prove the efficacy of Celexa in the treatment of generalized anxiety disorder; patents for Celexa expired in 2003.

However, just because Lexapro is FDA-approved to treat generalized anxiety disorder does not mean that it is more effective than Celexa, a medication lacking FDA-approval to treat generalized anxiety disorder.  A small-scale case observation study by Varia and Rauscher (2002) involving 13 patients reported that Celexa treatment significantly reduced symptoms of generalized anxiety disorder in all 13 patients – over a 12-week span.

Another study by Hoehn-Saric et al. (2004) [involving MRI neuroimaging] documented significant alterations in BOLD (blood oxygen level dependent) responses to worry and neutral stimuli in 6 patients with generalized anxiety disorder – following 7 weeks of Celexa treatment.  Findings from this study support the idea that Celexa may help counteract symptoms of generalized anxiety disorder.

Although there’s no strong evidence from large-scale, randomized controlled trials indicating that Celexa is efficacious in the treatment of generalized anxiety disorder – preliminary evidence suggests that it might be a useful intervention.  Moreover, because Celexa is understood to function similarly to Lexapro, a medication that’s FDA-approved for generalized anxiety disorder, it’s reasonable to speculate that Celexa would also prove efficacious in the treatment of generalized anxiety disorder.

Overall, Lexapro is a significantly better treatment choice than Celexa for generalized anxiety disorder because: (1) Lexapro has received FDA-approval for GAD (Celexa has not); and (2) no randomized controlled trials have evaluated Celexa in the treatment of generalized anxiety disorder.  That said, because no head-to-head trials have compared the efficacies of Lexapro and Celexa in the treatment of generalized anxiety disorder, we cannot definitively know (at this time) whether one medication is superior in efficacy to the other for this condition.

What about other medical conditions? (Celexa vs. Lexapro)

In the United States, neither Celexa nor Lexapro is FDA-approved for the treatment of social anxiety disorder, obsessive-compulsive disorder, premenstrual dysphoric disorder, panic disorder, or post-traumatic stress disorder.  Nevertheless, both medications are regularly prescribed “off-label” for the management of these medical conditions.

As of current, it remains unclear as to whether there are significant differences in the respective efficacies of Celexa and Lexapro in the off-label treatment of any medical condition(s).  That said, there is stronger evidence to substantiate the medical use of Lexapro in the treatment of social anxiety disorder, premenstrual dysphoric disorder, and PTSD – if compared to Celexa.

Social anxiety disorder (SAD)

Results of a meta-analysis by Baldwin et al. (2016) suggests that Lexapro is an effective treatment for social anxiety disorder.  This meta-analysis included data from 3 randomized, placebo-controlled trials encompassing 1598 patients (1061 Lexapro recipients vs. 537 placebo recipients).

Although preliminary evidence suggests that Celexa is also effective for social anxiety disorder, the quality of this evidence is low.  For example, an open-label study by Schneier et al. (2003) involving 21 patients (with social anxiety disorder and comorbid major depression) suggested that Celexa may reduce symptoms of social anxiety disorder.

Additionally, a series of 6 case reports presented by Varia et al. (2001) suggested that Celexa was effective in the treatment of social anxiety disorder.  As of current, it is unknown as to whether there are clinically-relevant differences in the efficacies of Celexa and Lexapro in the management of social anxiety disorder, however, there are stronger data supporting the use of Lexapro for this condition than there are supporting the use of Celexa.

Obsessive-compulsive disorder (OCD)

Data from randomized, controlled trials indicate that both Celexa and Lexapro are efficacious in the treatment of obsessive-compulsive disorder (OCD).  For example, a 12-week, double-blind, randomized, placebo-controlled trial by Montgomery et al. (2001) reported that Celexa was significantly more effective than a placebo in the treatment of obsessive-compulsive disorder (OCD).

The aforementioned study by Montgomery et al. included a sample of 401 patients with OCD and the efficacy of Celexa (20 mg, 40 mg, and 60 mg) as a treatment for OCD was evidenced by significant reductions in Yale-Brown Obsessive Compulsive Scale (Y-BCOS) scores after 12 weeks – when compared with baseline.  As of current, this is the only randomized controlled trial substantiating the usefulness of Celexa in obsessive compulsive disorder.

Additionally, a small-scale, open-label study by Thomsen et al. (2001) involving 30 adolescents with OCD (15 female, 15 male) reported statistically-significant improvements in OCD symptoms over a 1-year span from flexible-dose Celexa.  Improvements in OCD symptoms were evidenced by reductions in total Yale-Brown Obsessive Compulsive Scale scores (exceeding 35%) from baseline through 1 year of treatment.

Strongest evidence to support the usefulness of Lexapro in OCD is derived from a 24-week, randomized, placebo-controlled, paroxetine-referenced trial by Stein et al. (2007).  The trial by Stein et al. involved 466 adults with OCD who were assigned randomly to receive either: 10 mg/day Lexapro (116 participants); 20 mg/day Lexapro (116 participants); 40 mg/day Paxil (119 participants); or a placebo (115 participants) – for 24 weeks.

Results of the aforementioned trial by Stein et al. revealed that Lexapro (20 mg/day) was more effective than a placebo control on all primary and secondary outcome endpoints, including OCD remission.  Authors of this study concluded that Lexapro (20 mg/day) is associated with: a faster onset of action; higher response rate; higher remission rate; and improved functioning – relative to Paxil (a medication approved to treat OCD).

For this reason, authors stated that Lexapro should be considered a first-line long-term treatment for OCD.  Because the respective efficacies of Celexa and Lexapro for OCD haven’t been directly compared in a large-scale, well-designed trial, it remains unknown as to whether one intervention is clinically-superior over the other for this condition.

Premenstrual dysphoric disorder (PMDD)

Preliminary evidence suggests that Celexa and Lexapro may be useful in the treatment of premenstrual dysphoric disorder (PMDD).  For example, an open-label trial by Ravindran et al. (2007) documented significant improvement in PMDD symptoms among 8 women treated with Celexa (10-20 mg/day) at menses onset.

Additionally, an open-label study by Freeman et al. (2002) involving 17 women with refractory PMDD reported significant reductions in PMDD symptoms following treatment with Celexa (20-40 mg/day) – regardless of whether dosing was half-cycle or full-cycle.  Specific improvements were observed in physical symptoms, mood, behavior, pain levels, and appetite.

An earlier small-scale, double-blind trial by Wikander et al. (1998) also found that intermittently-administered Celexa was significantly more effective than a placebo in the treatment of PMDD – over the span of 3 menstrual cycles.  That said, none of the trials evaluating Celexa in the treatment of PMDD incorporated large sample sizes and only 1 trial was placebo-controlled.

Multiple trials have showcased the therapeutic potential of Lexapro in the management of PMDD.  For example, a placebo-controlled by Eriksson et al. (2008) involving 151 women with PMDD reported significant reductions in irritability, depression, tension, and emotional lability as a result of intermittently-administered Lexapro (20 mg/day) during luteal phases – over a 3-month span.

Additionally, a small-scale uncontrolled trial by Freeman et al. (2005) documented significant reductions in PMDD symptoms as a result of Lexapro treatment (during the luteal phase or at symptom onset) – over the span of 3 menstrual cycles.  In sum, while there’s stronger evidence supporting the usefulness of Lexapro in PMDD (relative to Celexa), it’s unclear as to whether the medications differ in efficacy for this medical condition.

Post-traumatic stress disorder (PTSD)

Preliminary evidence suggests that both Celexa and Lexapro may be effective in the treatment of PTSD.  For example, an open-label trial by English et al. (2006) involving 18 combat veterans with PTSD observed significant reductions in PTSD symptoms following 8 weeks of Celexa treatment – as was evidenced by change in score on the Clinician-Administered PTSD Scale (CAPS) from baseline.  It was concluded that Celexa appears to have a moderate effect in reducing symptoms of PTSD.

An 8-week open-label trial by Seedat et al. (2000) involving 9 adults with PTSD (civilian-related or combat-related) discovered that Celexa (20 mg/day initially, then 40 mg/day after Week 2) significantly reduced core PTSD symptoms such as: re-experiencing, hyperarousal, and avoidance.  Authors concluded that data from this open-label trial support the usefulness of Celexa in PTSD.

A study by Qi et al. (2007) involving 45 patients with PTSD revealed that Lexapro (up to 40 mg/day) significantly reduced the severity of PTSD symptoms (as evidenced by reductions in Clinician-Administered PTSD Scale (CAPS) scores after 12 weeks) – relative to baseline.  Authors of the study concluded that high-dose Lexapro appears effective in the treatment of PTSD.

A 12-week open-label trial conducted by Robert et al. (2006) reported that Lexapro (10 mg/day for 4 weeks, followed by 20 mg/day for the remaining 8 weeks) significantly reduced symptoms of PTSD in 24 participants diagnosed with the condition.  The reduction in PTSD symptoms was evidenced by significant decreases in CAPS (Clinician-Administered PTSD Scale-Symptom) scores after 12 weeks – relative to baseline.

Because the trials of Lexapro for PTSD involve larger sample sizes and longer durations than trials of Celexa for PTSD, one could argue that Lexapro would be the slightly better treatment option for PTSD.  Nevertheless, until a robustly-designed trial directly compares the efficacies of Celexa and Lexapro in the treatment of PTSD, neither medication should be considered superior over the other as a treatment for this medical condition.

Panic disorder

Preliminary data from multiple trials suggest that both Celexa and Lexapro are useful treatments for panic disorder.  For example, an acute (8-week) randomized, double-blind, controlled trial by Lepola et al. (1998) that included 475 persons with panic disorder – reported significant reductions in panic disorder symptoms among recipients of Celexa or clomipramine (relative to recipients of a placebo).

Thereafter, 279 of the original 475 participants entered a longer-term phase of the trial in which treatment continued for up to 1-year.  Results from the longer-term (up to 1-year) phase also indicated that Celexa (20 to 60 mg/day) was effective in the long-term management of panic disorder – as was evidenced by: abatement of panic attacks (after 8 weeks); reductions in HAM-A scores (versus baseline); and reduction in CGI-S scores (versus baseline).

Like Celexa, there are studies showcasing the efficacy of Lexapro in panic disorder.  For example, a 24-week open-label trial by Choi et al. (2012) involving 119 adults with panic disorder – reported significant improvement in panic disorder symptoms (relative to baseline) and reduced functional disability after 24 weeks of Lexapro treatment.

Not only did 96 of 119 (80.7%) of patients respond to Lexapro, but 87 of 119 patients (73.1%) exhibited remission of panic disorder symptoms within 24 weeks.  Based on the findings in the aforementioned study, authors suggested that Lexapro appears “very effective” for panic disorder.

Moreover, a randomized, double-blind, placebo-controlled trial by Stahl et al. (2003) that evaluated Celexa and Lexapro in the treatment of panic disorder found that both medications were effective.  This study included a sample of 366 patients diagnosed with panic disorder who were assigned at random to receive: Lexapro (128 participants); Celexa (119 participants); or a placebo (119 participants) – for 10 weeks.

Results of the trial revealed that recipients of either Lexapro or Celexa exhibited significant reductions in total number of panic disorder symptoms and symptom severities – relative to placebo recipients.  The outcome of this moderate-scale, controlled trial supports the idea that both Lexapro and Celexa are efficacious in panic disorder – and that neither medication is clinically superior over the other for this condition.

Note: Knowing that both Celexa and Lexapro: (1) contain S-citalopram; and (2) exhibit extremely-similar pharmacodynamics, it’s reasonable to surmise that the efficacies of these medications do not significantly differ in the treatment of any medical condition(s).

Mechanism of action (Pharmacodynamics)

There’s zero difference in the primary mechanism of action for Celexa (citalopram) and Lexapro (escitalopram) – both medications function as selective-serotonin reuptake inhibitors (SSRIs).  Following administration, Celexa and Lexapro cross the blood-brain-barrier (BBB) and bind to serotonin transporters (SERTs) whereafter these transporters become unable to facilitate the reabsorption of extracellular serotonin into presynaptic serotonergic neurons.

Blocking the presynaptic reabsorption of serotonin through interactions with serotonin transporters (SERTs) causes serotonin concentrations to increase within synaptic clefts (i.e. spaces between presynaptic and postsynaptic receptors).  Substantially increasing concentrations of serotonin within synaptic clefts (due to inhibiting SERT-mediated reuptake) yields predictable enhancement of postsynaptic receptor stimulation by serotonin – relative to homeostatic neurotransmission.

The enhancement of postsynaptic serotonin receptor stimulation (by the endogenous ligand, serotonin) occurs within hours of Celexa or Lexapro administration – and is accompanied by altered neural connectivity (wherein neural connections remodel in response to modulation of serotonin).  Bolstered stimulation of postsynaptic serotonin receptors with concurrent modulation of neural connectivity might explain why a subset of Celexa or Lexapro users report noticeable reductions in neuropsychiatric symptoms (e.g. anxiety, depression, etc.) on the first day of treatment.

Furthermore, ongoing administration of Celexa or Lexapro for a moderate-term (4 to 8 weeks) is understood to: (1) downregulate 5-HT1A receptor activation (resulting in amplification of postsynaptic serotonin signaling); (2) increase BDNF levels (resulting in hippocampal neurogenesis).  These additional actions (reduced activation of 5-HT1A and increased BDNF) could be reason as to why most Celexa and Lexapro users won’t experience improvement in neuropsychiatric conditions for 1 to 3 months after the date of treatment initiation.

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Despite the fact that the principal mechanism of action for Celexa and Lexapro is identical, studies have unveiled pharmacodynamic disparities between these agents.  The pharmacodynamic disparities between these medications are attributable to compositional differences between Celexa (50% R-citalopram & 50% S-citalopram) and Lexapro (100% S-citalopram).

Specifically, because Celexa contains a racemic mixture of S-citalopram (50%) and R-citalopram (50%) – its pharmacodynamics and secondary (i.e. non-primary) neurochemical actions differ from those of Lexapro which contains standalone S-citalopram (100%).  Radioligand binding research by Owens et al. (2002) indicates that the R-citalopram within Celexa modestly interacts with H1 histamine receptors and 5-HT2C receptors.

To a negligible extent, the R-citalopram within Celexa interacts with alpha-1 adrenergic receptors, M1 muscarinic receptors, and norepinephrine transporters (NETs).  Compared to Celexa, the radioligand binding research by Owens et al. (2002) indicates that the S-citalopram within Lexapro exhibits virtually no binding affinity for more than 100 receptor or binding sites – including histaminergic, alpha-adrenergic, and muscarinic receptors.

For this reason, Lexapro is known as the “most selective SSRI” (selective-serotonin reuptake inhibitor) based on the fact that it doesn’t significantly interact with an array of neurochemical sites beyond the serotonin transporter.  Nevertheless, research by Fabre and Hamon (2003) suggests that both Celexa and Lexapro interact with sigma receptors (sigma-1 and sigma-2).

Because agonism of sigma receptors (sigma-1 and sigma-2) yields antidepressant and anxiolytic effects in animals, it’s possible that this is an important secondary (i.e. non-primary) neurochemical action for both Celexa and Lexapro in the treatment of neuropsychiatric conditions.  That said, based on research by Fabre and Hamon (2003), Lexapro interacts with sigma receptors to a significantly greater extent than Celexa.

Additionally, according to Bræstrup and Sanchez (2004) the R-citalopram isomer in Celexa: (1) is 30-to-40-fold less potent than the S-citalopram isomer in its interaction with the serotonin transporter; and (2) dose-dependently counteracts the actions of S-citalopram.  R-citalopram not only interferes with the stabilization of S-citalopram on allosteric binding sites of the serotonin transporter (SERT), but it exerts an inhibitory effect on the association of S-citalopram with the serotonin transporter (SERT).

In other words, the neurochemical actions of R-citalopram may modestly attenuate the therapeutically-relevant serotonergic actions of S-citalopram in the treatment of neuropsychiatric conditions.  This may be reason as to why, in a microdialysis study by Mork et al. (2002), serotonin concentrations increased significantly more in rat brains after administration of 2 mg/kg Lexapro – versus administration of 4 mg/kg Celexa.

This could also be reason as to why Lexapro appears significantly more effective than Celexa in fixed-dose, head-to-head studies (e.g. 10 mg Lexapro vs. 20 mg Celexa).  Additional research by Jacquot et al. (2007) further supports the idea that R-citalopram has no inherent antidepressant potential and counteracts the antidepressant and anxiolytic actions of S-citalopram (when co-administered such as in Celexa).

In summary, both Celexa and Lexapro extensively interact with serotonin transporters to block the presynaptic reuptake of serotonin.  The magnitude of serotonin reuptake inhibition facilitated by Celexa is lower than the magnitude of serotonin reuptake inhibition associated with Lexapro – due to the presence of R-citalopram in Celexa.

Celexa also interacts with histamine, alpha-adrenergic, and muscarinic receptors as a result of its R-citalopram isomer.  Both Celexa and Lexapro interact with sigma-1 and sigma-2 receptors, however, the action of Lexapro upon these receptors significantly exceeds that of Celexa.

Subtle differences in the respective secondary neurochemical actions of Celexa and Lexapro may explain why Lexapro exhibits greater efficacy and/or a faster onset of action in some studies – relative to Celexa.  Subtle pharmacodynamic differences might also explain why certain persons respond better to one medication (e.g. Lexapro) relative to the other (e.g. Celexa).

Metabolism & Half-Life

Celexa and Lexapro do not significantly differ in route of metabolism, elimination half-life, or bioavailability.  After administration, both Celexa and Lexapro are metabolized in the liver by several CYP450 (cytochrome P450) enzymes, including: CYP2C19, CYP3A4, and CYP2D6.

Celexa contains R-citalopram (50%) which undergoes metabolism alongside S-citalopram (50%) – whereas Lexapro only contains S-citalopram (100%) which undergoes standalone metabolism.  According to in-vitro studies, the metabolism of R/S-citalopram (Celexa) is catalyzed primarily by CYP2C19 and CYP3A4 enzymes, and modestly by CYP2D6 enzymes, to form R/S-demethylcitalopram.

Thereafter, the R/S-demethylcitalopram metabolite undergoes: (1) N-demethylation via CYP2D6 enzymes to form R/S-didemethylcitalopram; (2) N-oxidation to form R/S-citalopram-N-oxide; and (3) deamination to form citalopram propionic acid.  Compared to R/S-citalopram (Celexa), in-vitro studies suggest that S-citalopram (Lexapro) is metabolized relatively evenly by hepatic enzymes CYP2C19 (36%); CYP3A4 (34%); and CYP2D6 (30%).

Furthermore, analogous to R/S-citalopram (Celexa), S-citalopram (Lexapro) forms metabolites such as: S-demethylcitalopram (S-DCT), S-didemethylcitalopram (S-DDCT), escitalopram-N-oxide, and escitalopram propionic acid.  Nonetheless, there are subtle differences in the degrees to which CYP2C19, CYP3A4, and CYPD26 enzymes are implicated in the respective metabolisms of R/S-citalopram (Celexa) and S-citalopram (Lexapro).

Specifically, the R-citalopram within Celexa is metabolized: ~46% by CYP3A4; ~33% by CYP2C19, and ~21% by CYP2D6 – whereas S-citalopram within Lexapro is metabolized: ~36% by CYP2C19; ~34% by CYP3A4; and ~30% by CYP2D6.  In addition to the aforementioned differences in degrees to which enzymes are implicated in the respective hepatic metabolisms of R-citalopram and S-citalopram, there may be slight disparities between Celexa and Lexapro in elimination half-life.

According to a book by Shoar and Padhy (2018), Celexa has an elimination half-life range from 24 to 48 hours (~35 hours is most common) and a bioavailability of 80% when administered orally.  An earlier study by Kragh-Sørensen et al. (1981) reported an average elimination half-life of ~33 hours for Celexa after attainment of steady-state concentrations.

Research by Rao (2007) indicates that Lexapro has an elimination half-life range of 27 to 33 hours and a bioavailability of 80% when administered orally.  According to elimination half-life data from pharmacokinetic studies, Celexa exhibits a slightly longer average elimination half-life and larger elimination half-life range relative to Lexapro – due to slower clearance of R-citalopram.

Additionally, the elimination half-lives of Celexa metabolites R/S-demethylcitalopram and R/S-didemethylcitalopram are ~60 hours and ~100 hours, respectively.  It is thought that Lexapro metabolites (S-demethylcitalopram and S-didemethylcitalopram) exhibit similar, albeit slightly shorter elimination half-lives than R/S-citalopram metabolites.

Based on the elimination half-lives for Celexa and Lexapro, we can estimate that it takes: (1) 5.5 to 11 days to eliminate Celexa from systemic circulation; and (2) 6.18 to 7.56 days to eliminate Lexapro from systemic circulation – after treatment cessation.  That said, it might take up to 13.75 days and 23 days to eliminate demethylcitalopram and didemethylcitalopram metabolites after discontinuation, respectively.

Popularity

Celexa was first released as a pharmaceutical medication in the United States in July of 1998 – whereas Lexapro was first released as a pharmaceutical medication in the United States in August of 2002.  If comparing the respective popularities of Celexa and Lexapro, it is unclear as to whether one medication can be considered historically more popular relative to the other.

Nevertheless, it is known that Celexa received approval for medical use in Denmark starting in 1989.  Because Celexa became available in certain countries ~13 years prior to its predecessor, Lexapro, it’s reasonable to suspect that the cumulative medical use of Celexa throughout history has exceeded the cumulative medical use of Lexapro to present.

If comparing the historical popularities of each medication in the United States since 2002 (the year in which both medications were available), it seems as though the popularity of Celexa exceeds that of Lexapro.  Still, it appears as though the popularities of both Celexa and Lexapro (based on number of prescriptions) have fluctuated significantly in the 2000s.

According to IMS Health (a global information and technology services company) Lexapro was prescribed more than Celexa in 2005 and 2009 – but Celexa was prescribed more than Lexapro in 2011 and 2013.  In 2013, nearly 40 million prescriptions were filled for Celexa (citalopram) and nearly 25 million prescriptions were filled for Lexapro (escitalopram).

According to ClinCalc DrugStats Database, over 28 million prescriptions were filled for generic Celexa (citalopram) in 2015 – and over 24 million prescriptions were filled for generic Lexapro (escitalopram oxalate) in 2015.  Though Celexa (citalopram) is prescribed more frequently than Lexapro (escitalopram) in the United States, it is unclear as to why Celexa remains the more popular medication.

Perhaps the reason Lexapro was prescribed more than Celexa in 2005 and 2009 was related to the fact that medical doctors and/or consumers assumed it was superior in efficacy and/or tolerability to Celexa.  However, during these years it actually would’ve been smarter to use Celexa (over Lexapro) based on its generic availability (and low cost) and the large body of evidence substantiating its safety, efficacy, and tolerability.

Generic Lexapro (escitalopram) became available in 2012 and several large meta-analyses suggest that it is: (1) potentially-more effective; and (2) potentially-more tolerable – than Celexa.  Additionally, Lexapro is FDA-approved to treat more medical conditions in the U.S. than Celexa (MDD and GAD vs. MDD, respectively).  For the aforementioned reasons, one might expect the popularity of Lexapro to eventually usurp that of Celexa in forthcoming years throughout the United States.

Side effects

The most common Celexa side effects (according to FDA Access Data) include: ejaculation disorder, nausea, dry mouth, somnolence, insomnia, and sweating.  The most common Lexapro side effects (according to FDA Access Data) include: insomnia, ejaculation disorder, nausea, sweating, fatigue, somnolence, reduced libido, and anorgasmia.

Considering the most common side effects [reported in FDA Access Data] for Celexa and Lexapro, respectively, it seems as though there is significant overlap in the most common side effects of these medications.  Both Celexa and Lexapro commonly cause side effects such as:  ejaculation disorder, nausea, insomnia, somnolence, and sweating.

Nevertheless, if the common respective side effects [reported in FDA Access Data] for Celexa and Lexapro are accurate, it seems as though Celexa is more likely than Lexapro to cause dry mouth as a side effect – and Lexapro is more likely than Celexa to cause reduced libido and anorgasmia as side effects.

Because Celexa and Lexapro are: (1) chemically-similar in that each agent contains “S-citalopram”; (2) exhibit the same primary mechanism of action (selective-serotonin reuptake inhibition); and (3) are metabolized in the liver via the same hepatic pathways – there shouldn’t be significant differences in the most common side effects of these medications.

If there are legitimate differences in the prevalence and/or severities of certain side effects between Celexa and Lexapro, these differences are attributable to the presence of “R-citalopram” within Celexa and/or the lack of R-citalopram within Lexapro.  R-citalopram in Celexa reduces the magnitude of its primary serotonergic effect and causes the medication to interact with histamine receptors.

More specifically, R-citalopram reduces the magnitude of serotonin reuptake inhibition [facilitated by S-citalopram] and interacts with histamine receptors.  This might be reason as to why Celexa is associated with higher rates of dry mouth (histamine-related) as a side effect and/or lower rates of libido reduction and anorgasmia (serotonin-related) as side effects – than Lexapro.

Oppositely, because Lexapro solely contains S-citalopram, the magnitude of its primary serotonergic effect exceeds that of Celexa (even if S-citalopram concentrations are equivalent) and its action is more selective (wherein it doesn’t interact with histamine receptors).  This might be reason as to why Lexapro is associated with higher rates of libido reduction and anorgasmia (serotonin-related) as side effects and lower rates of dry mouth (histamine-related) as a side effect – than Celexa.

In terms of tolerability, it is unclear as to whether there are significant differences between Celexa and Lexapro.  To determine the tolerability of Celexa and Lexapro, we can look at data from: (1) placebo-controlled trials (to compare the tolerability of each medication relative to a placebo) and (2) head-to-head trials (to compare the tolerability of each medication relative to each other).

In a comprehensive meta-analysis by Cipriani et al. (2018) incorporating data from 522 randomized controlled trials (116,477 participants), the acceptability for Celexa and Lexapro were reported with 19 additional antidepressants.  Findings of the meta-analysis revealed modestly superior acceptability for Lexapro relative to Celexa – in both placebo-controlled trials and head-to-head trials.

In placebo-controlled trials, the average dropout rate among Lexapro users relative to a placebo was “0.90” – whereas the average dropout rate among Celexa users relative to a placebo was “0.94.”  This means that fewer Lexapro users discontinued treatment in placebo-controlled trials as a result of adverse reactions – relative to Celexa users.

In head-to-head trials, the average dropout rates for both Celexa and Lexapro were less than “0.60” – and the medications ranked 4 (Celexa) and 3 (Lexapro) out of 21, respectively, in acceptability.  This means that fewer Lexapro users discontinued treatment in head-to-head trials as a result of adverse reactions – relative to Celexa users.

Of the two medications, there’s a trend to suggest that Lexapro might be slightly more tolerable than Celexa (on average).  Nevertheless, there are zero data from placebo-controlled trials or head-to-head trials to substantiate the idea that Celexa and Lexapro exhibit statistically-significant (i.e. clinically-relevant) differences in tolerability.

In sum, research indicates that there aren’t significant differences between Celexa and Lexapro (on average) in the occurrence of specific side effects; side effect prevalence; or side effect severities.  Celexa and Lexapro are considered among the most-tolerable SSRIs in mainstream pharmaceutical use.

Withdrawal

Whenever treatment with Celexa or Lexapro is discontinued, former users of these medications are at risk of experiencing physical and psychological withdrawal symptoms.  Although any former user of Celexa or Lexapro can experience withdrawal symptoms, these symptoms tend to be harshest among persons who underwent long-term, high-dose treatment and stopped treatment rapidly or “cold turkey.”

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In some cases, withdrawal symptoms from Celexa or Lexapro will persist for months (sometimes years) after the date of treatment cessation – wherein a subset of former users end up with “post-acute withdrawal syndrome” (PAWS).  Additionally, during withdrawal from Celexa or Lexapro, former users may struggle to function in academic, occupational, familial, and/or social settings.

Common withdrawal symptoms associated with both Celexa and Lexapro include: rebound depression; rebound anxiety; dizziness; headache; fatigue; sleepiness; nausea; insomnia; “brain zaps;” flu-like symptoms; muscle aches; and poor balance.  Withdrawal symptoms from Celexa and Lexapro are understood to occur as a result of imbalanced neurophysiology while transitioning from an SSRI-adapted state – back to drug-free homeostasis.

Whenever a person uses Celexa or Lexapro every day (i.e. regularly) for months or years (i.e. long-term), the neurophysiology of that individual becomes acclimated to the medication and adapts to its effects.  Neurophysiologic adjustments as adaptive responses to Celexa or Lexapro might include: (1) a reduction in endogenous serotonin secretion; (2) desensitization of presynaptic 5-HT1A receptors; (3) changes in secondary chemical messenger activity (e.g. cyclic-AMP); (4) changes in gene expression; and (5) 5-HT1A autoreceptor downregulation.

Following significant neurophysiologic adaptation to Celexa or Lexapro, ongoing administration of the medication is needed to preserve neurophysiologic (especially neurochemical) balance.  Once medications like Celexa and Lexapro are discontinued, medication-related neurophysiologic adaptations persist – and neurophysiologic activity becomes notably imbalanced without administration of the medication.

Neurophysiologic imbalances resulting from Celexa or Lexapro discontinuation incite noticeable withdrawal reactions (i.e. symptoms).  With sufficient time removed from treatment, the body eventually recalibrates itself to functioning without the medication such that pre-treatment (i.e. pre-SSRI) neurophysiologic balance is restored.

This readjustment phase sometimes requires more time than patients and/or medical professionals expect (e.g. weeks, months, years, etc.).  Unfortunately, withdrawal symptoms do not completely abate until neurophysiology has completely transitioned back to pre-medication homeostasis – from a “medication-adapted” state.

Because Celexa and Lexapro are chemically-similar agents and exhibit the same primary mechanism of action, it is unlikely that there are significant differences in their respective withdrawal symptoms and/or the severities of those symptoms.  If there are differences in the occurrence of specific withdrawal symptoms and/or withdrawal symptom severity between Celexa and Lexapro, the differences are likely subtle (i.e. clinically-irrelevant).

Nevertheless, it’s possible that the presence of R-citalopram in Celexa and/or lack of R-citalopram in Lexapro explains subtle differences in discontinuation symptoms between these agents (following treatment with doses of equal S-citalopram potency).  If this hypothesis is legitimate, then Celexa users would accrue: (1) more substantial histaminergic adaptation; (2) less substantial serotonergic adaptation; and (3) less significant sigma receptor adaptation – than Lexapro users.

This might translate to Celexa users being at greater risk of enduring heightened histaminergic transmission in withdrawal (and corresponding histamine-related reactions) relative to Lexapro users.  Additionally, this might translate to Lexapro users being at higher risk of enduring greater serotonergic dysregulation and/or diminished sigma receptor activation in withdrawal (and corresponding reactions) relative to Celexa users.

In addition to the aforementioned potential subtle differences in withdrawal symptoms among Celexa and Lexapro users in withdrawal, discontinuing Celexa might be negligibly easier than discontinuing Lexapro due to its longer elimination half-life.  The elimination half-life of Celexa ranges from 24 to 48 hours (~35 hours) and the elimination half-life of Lexapro ranges from 27 to 33 hours – meaning Celexa remains in systemic circulation for a longer duration than Lexapro [on average] post-discontinuation.

In withdrawal, medications with longer elimination half-lives are generally advantageous over medications with shorter elimination half-lives because they allow the body to gradually adjust to functioning with lower concentrations of that medication (to which it has adapted) over a longer duration prior to complete systemic elimination.  Gradual adjustment to lower concentrations of a medication over an extended duration (prior to complete systemic elimination) is believed to yield a smoother and shorter-lived transition from medication-adapted neurophysiology to homeostatic neurophysiology.

Overall, there are no data from medical literature to suggest that the occurrence of specific withdrawal symptoms and/or withdrawal symptom severity – differ between Celexa and Lexapro users.  Nonetheless, as was mentioned, subtle differences in the pharmacodynamics and elimination half-lives of Celexa and Lexapro might account for reported disparities in withdrawal symptoms and/or severity by a subset of users.

Similarities (Overview): Celexa vs. Lexapro

Below is a summary of noteworthy commonalities of Celexa (citalopram) and Lexapro (escitalopram).  Celexa and Lexapro are generally similar in aspects such as: bioavailability; drug classification; duration of action; formatting; legal status; mechanism of action; medical uses; metabolism; side effects; and withdrawal symptoms/severity.

  • Bioavailability: When administered orally, the bioavailability of Celexa and Lexapro is estimated to be ~80%. This means that around 80% of ingested Celexa and Lexapro actively modulates neurophysiology.
  • Developers: Both Celexa and Lexapro were developed by Lundbeck, a Danish pharmaceutical company. That said, Celexa was developed solely by Lundbeck – whereas Lexapro was jointly developed by Lundbeck and Forest Laboratories.
  • Drug classification: Celexa and Lexapro are formally classified as selective-serotonin reuptake inhibitors (SSRIs). As selective-serotonin reuptake inhibitors, Celexa and Lexapro increase serotonin concentrations in extracellular spaces to enhance serotonergic signaling.
  • Duration of effect: The average duration of effect for a single, orally-administered dose of Celexa or Lexapro is ~24 hours. For this reason, both medications are generally recommended to be administered once per day – at the same time each day.
  • Effectiveness (?): Although Lexapro appears modestly more effective than Celexa in the treatment of major depressive disorder (MDD), this superior efficacy was only demonstrated in studies that were funded and/or co-authored by Lundbeck and/or Forest Laboratories (pharmaceutical companies that stood to financially benefit from showcasing the superiority of Lexapro over Celexa). In the standalone head-to-head study that wasn’t funded by these companies, the antidepressant efficacies didn’t differ between Celexa and Lexapro.  Meta-analyses have also revealed no differences between Celexa and Lexapro in antidepressant efficacy.  As of current, most professionals do not consider Celexa and Lexapro to differ in effectiveness for the treatment of major depressive disorder or other medical conditions.
  • Formatting: Celexa and Lexapro are each manufactured in 2 formats: tablet and oral solution. Tablet format of each medication is manufactured in 3 standard dosing increments – whereas the oral solution format is manufactured in 1 dosing increment.
  • Generic availability: Both Celexa and Lexapro have long been available as generics in the United States. Celexa became available as a generic in 2003 under its chemical name “citalopram hydrobromide” – and Lexapro became available as a generic in 2012 under its chemical name “escitalopram oxalate.”
  • Legal status: In the United States, Celexa and Lexapro are legally-classified as prescription-only (Rx-only) medications. Under this legal classification, Celexa and Lexapro can only be acquired with a legitimate prescription from a licensed medical doctor.
  • Medical uses: Celexa and Lexapro are generally considered interchangeable treatment options for medical conditions. Common medical uses for both Celexa and Lexapro include:  major depressive disorder (MDD); generalized anxiety disorder; social anxiety disorder; obsessive-compulsive disorder (OCD); premenstrual dysphoric disorder (PMDD); panic disorder; and post-traumatic stress disorder (PTSD).
  • Metabolism: Celexa and Lexapro are metabolized in the liver (i.e. hepatically) by the same 3 cytochrome P450 (CYP450) enzymes: CYP2C19, CYP2D6, and CYP3A4. Although R/S-citalopram within Celexa is metabolized slightly differently by the aforementioned enzymes than standalone S-citalopram in Lexapro – these differences aren’t substantial.  Moreover, both Celexa and Lexapro form “demethyl” and “didemethyl” metabolites with longer half-lives than the parent chemicals (citalopram and escitalopram).
  • Onset of action: Though select studies (funded by pharmaceutical companies) suggest that Lexapro exhibits a faster onset of antidepressant action than Celexa, most research indicates that Lexapro and Celexa are similar in their respective onsets of antidepressant action. Both medications modulate serotonergic neurotransmission and neural connectivity on the first day of administration, yet most users don’t experience reductions in neuropsychiatric symptoms for 4 to 8 weeks of treatment.
  • Potential for abuse or addiction: As SSRIs, neither Celexa nor Lexapro rapidly stimulates reward centers in the brain to induce euphoriant effects and/or psychological reinforcement.  Although selective-serotonin reuptake inhibitors can be misused, the likelihood of their misuse is low.  Predictably, there are no strong data to suggest that Celexa and Lexapro are frequently abused, misused, or addictive pharmaceutical medications.
  • Primary mechanism of action: Celexa and Lexapro exhibit the same primary mechanism of action involving selective-serotonin reuptake inhibition (SSRI). Specifically, both medications bind to the serotonin transporter and prevent it from facilitating the reuptake of extracellular serotonin into presynaptic neurons.  Blocking serotonin reuptake increases extracellular serotonin concentrations and enables stronger postsynaptic serotonin signaling.
  • Side effects: The side effect profiles of Celexa and Lexapro are extremely similar – likely due to the fact that both medications are chemically-similar (containing S-citalopram) with identical primary mechanisms of action. Common side effects for Celexa and Lexapro include:  ejaculation disorder, nausea, insomnia, somnolence, and sweating.
  • Tolerability: Data from a meta-analysis by Cipriani et al. (2018) revealed that Celexa and Lexapro are two of the most-tolerable antidepressants in mainstream use. Using acceptability data from head-to-head trials, Celexa was ranked 4th overall and Lexapro was ranked 3rd overall (out of 21 antidepressants) in tolerability.  In placebo-controlled trials, dropout rates relative to a placebo were “0.90” for Lexapro and “0.94” for Celexa.  Though Lexapro was more tolerable than Celexa (on average), this difference in tolerability was not significant.
  • Withdrawal: Because Celexa and Lexapro are chemically-similar with identical primary mechanisms of action – there shouldn’t be any substantial differences between these agents in the magnitudes, occurrence rates, or durations of their withdrawal symptoms. Both Celexa and Lexapro can cause debilitating and/or long-lasting symptoms in the aftermath of treatment cessation – particularly among high-dose and/or long-term users.

Note: If you’re aware of similarities between Celexa and Lexapro that weren’t mentioned in the above list, be sure to report them in the comments.

Differences (Overview): Celexa vs. Lexapro

Below is a summary of noteworthy differences between Celexa (citalopram) and Lexapro (escitalopram).  Celexa and Lexapro clearly differ in aspects such as: secondary neurochemical actions; FDA-approved indications; popularity; and ingredients.  Subtler differences between Celexa and Lexapro might include: average cost; efficacy; and elimination half-life.

  • Average cost: At most pharmacies, Celexa will be slightly less expensive than Lexapro –regardless of whether generic vs. brand name OR tablet vs. oral solution. Currently, 30 tablets of generic Celexa (citalopram) sell for $4 to $22 (on average) and 30 tablets of generic Lexapro (escitalopram) sell for $8 to $49 (on average).  Additionally, 30 tablets of brand name Celexa sell for $267 to $309 – and 30 tablets of brand name Lexapro sell for $306 to $358.  A 240 mL bottle of oral citalopram (Celexa) solution costs $55 to $67 – whereas a 240 mL bottle of oral escitalopram (Lexapro) solution costs $67 to $116.
  • Effectiveness (?): In the lone head-to-head trial [comparing the antidepressant efficacies of Celexa and Lexapro] devoid of funding from Lundbeck or Forest Laboratories (companies that stood to financially profit from proving the superiority of Lexapro over Celexa) – no clinically-relevant differences in antidepressant efficacy were observed. However, if the 6 head-to-head trials [evaluating the antidepressant efficacies of Celexa and Lexapro] that were funded by Lundbeck and Forest Laboratories – presented unbiased and legitimate data, then Lexapro appears significantly more effective than Celexa in the treatment of major depressive disorder (MDD).
  • Elimination half-life: According to pharmacokinetic research, Celexa exhibits a longer elimination half-life than Lexapro as a result of its R-citalopram. The documented elimination half-life range for Celexa is 24 to 48 hours (35-hour average) – and the documented elimination half-life range for Lexapro is 27 to 33 hours.  This indicates that Celexa will remain in the body for a longer duration after discontinuation than Lexapro.
  • FDA approved uses: Due to their chemical, pharmacodynamic, and pharmacokinetic similarity – it is thought that most medical doctors and psychiatrists regard Celexa and Lexapro as interchangeable treatment options for neuropsychiatric disorders.  While both Celexa and Lexapro have received approval from the U.S. FDA to treat major depressive disorder (MDD), only Lexapro has received additional FDA-approval to treat generalized anxiety disorder (GAD).
  • Ingredients: The active ingredient in the medication Celexa is the chemical “citalopram hydrobromide” (R/S-citalopram) – and the active ingredient in the medication Lexapro is the chemical “escitalopram oxalate” (S-citalopram). Though both Celexa and Lexapro contain “S-citalopram” – only Celexa contains R-citalopram.
  • Popularity: The popularities of Celexa and Lexapro have drastically fluctuated in the United States since their respective inceptions. Nevertheless, it seems as though Celexa has been historically more popular than Lexapro – even in years since both medications have been available as generics.  In 2013, 40 million prescriptions were filled for citalopram (Celexa) – and 25 million prescriptions were filled for escitalopram (Lexapro), whereas in 2015, 28 million prescriptions were filled for citalopram (Celexa) – and 24 million prescriptions were filled for escitalopram (Lexapro).
  • Secondary neurochemical actions: Though Celexa and Lexapro exert the same primary mechanism of action, the medications differ in their secondary neurochemical actions. Celexa modestly modulates H1 histamine receptors and 5-HT2C receptors – whereas Lexapro does not.  Lexapro is more selective than Celexa in its action, but appears to agonize sigma receptors (sigma-1 and sigma-2) to a substantially greater extent than Celexa.

Note: If you’re aware of differences between Celexa and Lexapro that weren’t mentioned in the above list, be sure to report them in the comments.

Which medication is “better”? (Celexa vs. Lexapro)

To determine whether Celexa or Lexapro is “better” (on average) relative to the other, we should reflect upon variables that prospective users and/or medical professionals care about, including: average cost; efficacy in the treatment of medical conditions; formatting and dosages; onset and duration of action; official (FDA-authorized) medical indications; side effects and tolerability; and withdrawal difficulty.  In nearly all of the aforementioned variables, there aren’t significant differences between Celexa and Lexapro.

For this reason, many psychiatrists and general practitioners have concluded that neither Celexa nor Lexapro should be considered “better” than the other.  Then again, Celexa might be perceived as modestly advantageous over Lexapro on the basis of its: slightly lower average cost; slightly lower rates of sexual dysfunction-type side effects (e.g. anorgasmia and reduced libido); and/or slightly longer elimination half-life (potentially yielding a slightly easier discontinuation process).

Still, most consumers probably consider generic Celexa (citalopram) and Lexapro (escitalopram) to be cheap – and not so significantly different in cost that one option would be definitively preferred over the other for the sake of preserving one’s finances.  In fact, a subset of pharmacies might sell a 30-tablet supply of generic Lexapro (escitalopram) at the same or at a lower cost than a 30-tablet supply of generic Celexa (citalopram) – negating the hypothesized financial advantage of Celexa over Lexapro.

Additionally, lower incidence rates of sexual dysfunction-type side effects (anorgasmia and reduced libido) reported in Celexa trials relative to Lexapro trials – might not actually reflect side effect differences between these medications.  In other words, Celexa users might not legitimately be at lower risk than Lexapro users of experiencing unwanted sexual dysfunction-type side effects like anorgasmia and reduced libido – negating the hypothesized side effect advantage of Celexa over Lexapro.

Furthermore, even if Celexa yields a negligibly easier withdrawal relative to Lexapro due to its longer average elimination half-life, this hypothetical advantage for Celexa over Lexapro could be negated by conducting a slow taper off of Lexapro and/or using a Prozac (fluoxetine) bridge in the midst of discontinuation.  Overall, there aren’t really many logical reasons that patients and/or prescribers should prefer Celexa over its predecessor Lexapro.

Lexapro might be perceived as modestly advantageous over Celexa on the basis of its: efficacy in the treatment of major depressive disorder (MDD); onset of antidepressant action; attainment of FDA-approval to treat generalized anxiety disorder (GAD); and tolerability.  In the largest meta-analysis to date by Cipriani et al. (2018), Lexapro ranked slightly higher than Celexa in both “efficacy” and “tolerability” – based on pooled data from head-to-head trials and placebo-controlled trials.

Cipriani et al. documented efficacy probabilities of 1.68 for Lexapro and 1.52 for Celexa (based on placebo-controlled trial data) and ranked Lexapro as 3rd and Celexa as 12th (of 21 antidepressants) in head-to-head efficacy (based on head-to-head trial data).  These findings support the idea that Lexapro may be slightly more effective than Celexa as an antidepressant.

Additionally, Cipriani et al. documented dropout rates of “0.90” for Lexapro and “0.94” for Celexa (based on placebo-controlled trial data) and ranked Lexapro 3rd and Celexa 4th in head-to-head tolerability of 21 antidepressants (based on head-to-head trial data).  These findings support the idea that Lexapro may be slightly more tolerable than Celexa as an antidepressant.

Moreover, prior systematic reviews and head-to-head trials have reported: (1) higher response rates; (2) higher remission rates; (3) a larger magnitude of antidepressant effect; (4) greater improvements in quality of life; and (5) faster responses – among Lexapro users relative to Celexa users.  (It is also worth mentioning that while select studies have documented Lexapro as superior to Celexa in “efficacy” and/or “tolerability” – zero studies have documented Celexa as superior to Lexapro in these measures).

Although the differences between Celexa and Lexapro in “efficacy” and “tolerability” may not be clinically-relevant, it is logical to expect that Lexapro would be slightly superior in antidepressant efficacy and/or tolerability to Celexa on the basis of its chemical composition and/or pharmacodynamics.  Celexa contains R-citalopram which interferes with the antidepressant action (serotonin reuptake inhibition) of S-citalopram – whereas Lexapro only contains S-citalopram.

If we assume that S-citalopram content is equivalent in doses of Celexa and Lexapro (e.g. 20 mg Celexa vs. 10 mg Lexapro) – the magnitude of serotonin reuptake inhibition (and corresponding increases in extracellular serotonin) will be lower in Celexa users than Lexapro users due to interference from R-citalopram.  Furthermore, standalone S-citalopram in Lexapro agonizes sigma receptors to a significantly greater extent than the R/S-citalopram combination in Celexa.

Greater serotonin reuptake inhibition plus sigma receptor agonism exhibited by Lexapro relative to Celexa may be reason as to why Lexapro appears more efficacious than Celexa (in some studies) for the treatment of major depressive disorder.  Additionally, because Lexapro doesn’t significantly interact with secondary binding sites (e.g. H1 receptors; 5-HT2C receptors; et al.) like Celexa, and is more selective in its action, it may be more tolerable than Celexa (and less likely to cause “dry mouth” as a side effect).

That said, if Celexa and Lexapro are flexibly-dosed (rather than administered in fixed doses), it’s relatively unlikely that these medications would differ in antidepressant efficacy.  For example, 25 mg Celexa might deliver the same amount of serotonin reuptake inhibition and/or sigma receptor agonism as 10 mg Lexapro – thereby likely negating differences in magnitudes of antidepressant actions that accounted for disparities in efficacy in fixed-dose comparison studies.

Still, in the aforementioned hypothetical comparison, the presence of 12.5 mg R-citalopram (in 25 mg Celexa) would probably provoke a greater number of side effects and/or more severe side effects – relative to standalone 10 mg S-citalopram (in 10 mg Lexapro) which exhibits higher selectivity for the serotonin transporter (SERT).  For this reason, it makes a bit more sense to prefer Lexapro over Celexa in that its efficacy or tolerability should be theoretically [modestly] better (on average).

Then again, some might hypothesize that the modest secondary neurochemical actions of Celexa upon H1 receptors and 5-HT2C receptors could contribute to its antidepressant effect wherein Celexa could end up more effective and/or tolerable than Lexapro.  That said, there’s no preexisting evidence from head-to-head studies or meta-analyses to suggest that Celexa is superior over Lexapro in antidepressant efficacy or tolerability – so this hypothesis is unsupported by evidence.

Even if Lexapro and Celexa are equally efficacious and/or tolerable in the treatment of major depressive disorder (MDD), preexisting evidence from numerous studies supports the idea that Lexapro might be more effective and/or tolerable than Celexa in the treatment of major depressive disorder (MDD).  Even if this evidence was derived from studies with serious limitations (e.g. sponsorship bias, reporting bias, publication bias, etc.) – the results could be accurate.

Because it’s possible that Lexapro is more effective and/or tolerable than Celexa (and no evidence to suggest the opposite being true), it’s presently reasonable to recommend utilizing Lexapro ahead of Celexa in the treatment of major depressive disorder.  On the basis of its potentially-superior efficacy, potentially-superior tolerability, FDA-approval to treat generalized anxiety disorder (which Celexa lacks), and its higher selectivity – Lexapro could be considered a “better” medication than Celexa.

Nevertheless, it’s important to avoid assuming that all individuals will respond identically to Celexa and Lexapro in the treatment of neuropsychiatric disorders.  A subset of persons might report that “Celexa worked better than Lexapro,” another subset of persons might claim that “Lexapro worked better than Celexa,” and others might report that the medications are equally effective/ineffective in the management of a medical condition.

Disparities in genetic/epigenetic expression; pre-treatment neurochemistry; neural connectivity; brain morphology; autonomic nervous system activity; etc. – might account for subtle individual differences in reactions to Celexa and Lexapro (despite equal concentrations of S-citalopram).  In order to effectively determine whether Celexa or Lexapro is “better” than the other for a specific medical condition, persons will need to try each medication, separately, for 4 to 8 weeks in accordance with medical instruction.

Which medication do you prefer: Celexa or Lexapro?

If you have personal experiences using Celexa and Lexapro, distinctively, leave a comment mentioning whether you: prefer treatment with one medication (relative to the other) OR have no significant preference for using one agent (relative to the other).  On a scale of 1 to 10 (with “1” being “worst” and “10” being “best”), what would you rate the efficacy (1-10) and (1-10) tolerability of Celexa and Lexapro, respectively?

Assuming you prefer using either Celexa or Lexapro (over the other), share reasons for your preference.  Reasons might include things like: superior perceived efficacy (and symptom management); superior tolerability (fewer side effects and/or side effects of lower severities); and/or lower cost.

In the event that you found one medication (Celexa or Lexapro) to be more efficacious or tolerable than the other – have you considered that these differences may have been attributable to disparities in variables such as: neurophysiology/neurochemistry at baselines (prior to using each agent); potencies of dosages (e.g. 5 mg Lexapro vs. 30 mg Celexa); and/or concurrent substance use during treatment?

To help others better understand your treatments with Celexa and Lexapro, respectively, note additional details in your comment such as: lengths of treatment; dosages utilized; concurrent substance administration during either treatment; and/or the specific medical condition(s) for which these medications were prescribed.