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Qsymia Side Effects & Adverse Reactions (List)

Qsymia is a weight loss drug engineered by the California-based pharmaceutical company Vivus Inc.  It was initially approved by the FDA in 2012 for weight reduction among adults with BMIs (body mass indexes) exceeding 30 kg/m² as an adjunct to interventions such as caloric restriction, dietary modification, and regular exercise.  Qsymia is also approved for usage among adults with BMIs exceeding 27 kg/m², provided they have at least one weight-induced medical condition such as: diabetes, dyslipidemia, or hypertension.

Despite its recent 2012 approval date, Qsymia is nothing more than a patented, well-marketed combination of older drugs: phentermine (approved by the FDA in 1959) and topiramate (approved by the FDA in 1996).  The phentermine constituent is classified as a psychostimulant and functions primarily as a TAAR1 agonist, whereby it facilitates the intraneuronal release of norepinephrine.  Phentermine is understood to attenuate hunger via modulation of hypothalamic activity and burn fat stores by elevating peripheral norepinephrine and epinephrine concentrations.

The topiramate constituent is classified as an anticonvulsant and functions by targeting: voltage-gated sodium channels, high-voltage-activated calcium channels, GABA-A receptors, AMPA receptors, and carbonic anhydrase isoenzymes.  Though the specific pharmacodynamic effects of topiramate responsible inducing weight loss remain unclear, the drug appears to reduce appetite, alter taste perception, and decrease food cravings (For more information, read: “Topamax for weight loss“).  Blending phentermine and topiramate to form the drug Qsymia is thought to yield a synergistic weight loss effect, greater than could be attained with each constituent as a standalone.

Although there’s evidence to suggest that Qsymia is significantly more effective than a placebo for weight loss, it is not devoid of side effects.  Many individuals taking Qsymia like fact that it helps them lose weight, but may dislike a myriad of side effects that they experience.  Should you experience debilitating side effects from Qsymia, you may need to discontinue treatment and/or switch to an alternative weight loss medication.

Qsymia Side Effects & Adverse Reactions (List)

If you’re taking Qsymia, it is important to be cognizant of potential side effects and adverse reactions that may occur as a result of treatment.  Realize that the total number of side effects, specific side effects, and severity of side effects that you experience – will be subject to individual variation.  In other words, the side effects you experience while taking Qsymia may differ significantly from those of another person.

Despite individual variation in the occurrence of side effects, some side effects are more common than others.  The most common side effects of Qsymia based on data from clinical trials include: constipation, dizziness, dry mouth, dysgeusia, insomnia, palpitations, and paresthesia (tingling sensations).  A more comprehensive list of Qsymia side effects is included below.

Allergic reaction: In extremely rare cases, some individuals may experience an allergic reaction to taking Qsymia.  An allergic reaction may be characterized by: difficulty breathing, hives, and/or swelling of various body parts such as the face, lips, and tongue.  If you suspect that you’re experiencing an allergic reaction to Qsymia, it is imperative that you seek immediate medical attention – as it could result in serious complications.

Those who are allergic to Qsymia should find that the allergic reaction subsides within a week or two of discontinuation.  After Qsymia has been discontinued, to help treat the symptoms of an allergic reaction, your doctor may prescribe another medication and/or recommend an over-the-counter drug to combat itchiness.  Fortunately, there are other weight loss drugs available to try if you are unable to tolerate this particular drug.

Altered sense of taste: Among the most common side effects of Qsymia is a distorted or altered sense of taste, medically referred to as “dysgeusia.”  If you notice that the taste of foods and/or drinks aren’t same as before you started taking Qsymia, you may be experiencing drug-induced dysgeusia.  Some individuals will report experiencing metallic, salty, or rancid tastes from Qsymia – each of which can be considered dysgeusia.

It is also important to note that some users may experience a complete lack of taste (ageusia) or reduced taste sensitivity (hypogeusia).  It isn’t clear as to how the drug alters sense of taste, but the topiramate component is thought to be primarily responsible.  Many users claim that while taking the drug, hyperpalatable foods and/or sugary drinks (e.g. soda) taste completely bland, flat, or unpleasant.

Should the taste distortion impair with healthy eating habits, result in unhealthy weight loss, or cause depression – it may be necessary to discontinue treatment.  That said, many individuals may not mind sacrificing their normative taste perception as long as they continue to lose weight.  Additionally, sometimes the occurrence of dysgeusia as a side effect may be transient in that it subsides after several months of treatment.

Anger: It shouldn’t come as a shock that some patients taking Qsymia may report anger outbursts and/or rage.  Anger is a well-documented side effect of phentermine, and although the topiramate component of Qsymia may help decrease irritability/anger, it won’t be effective for every user.  The anger is likely caused by increases in norepinephrine as facilitated by phentermine, which in turn activate the sympathetic nervous system and trigger a fight-or-flight response.

This makes individuals feel irritable, and when this irritability increases, anger may result.  If every little thing is making you angry, or you feel as if you’re turning into some sort of monster (e.g. the Incredible Hulk) – Qsymia may not be an optimal drug for your neurochemistry.  Those taking higher doses of the drug may find that their anger decreases if they lower the dose.

It should be speculated that those with a preexisting neuropsychiatric disorder may be at highest risk of experiencing anger from treatment due to the fact that they may be more sensitive to neurochemical changes.  If the anger you’re experiencing on the medication only mild, and weight loss is significant, you may benefit from daily relaxation exercises or an adjunct anxiolytic.  Keep in mind that anger may be related to nutritional deficiencies or going extended periods without food – each of which may occur as a result of drug-induced appetite reduction.

Correcting nutrient deficits and eating until satiated may decrease bouts of anger during treatment.  In the event that the anger is damaging to your relationships and/or interferes with your quality of life, this should be discussed with your doctor.  A doctor will be able to advise you as to whether switching medications, discontinuing treatment, or continuing treatment while utilizing an adjunct for the irritability – would be beneficial.

Anxiety: Though a less common side effect, anxiety is reported by some Qsymia users.  In large part, the anxiety that occurs as a side effect can be attributed to the phentermine component.  Phentermine acts as a psychostimulant (analogous to amphetamine) and stimulates the release of catecholamines such as norepinephrine, epinephrine, and dopamine.

This increases neurophysiological arousal and activates the sympathetic nervous system, possibly leading to mental and/or physical symptoms of anxiety.  Anxiety as a side effect may be more likely to occur among those with preexisting neuropsychiatric conditions (e.g. anxiety disorders).  It may also be a more common side effect among individuals with CYP3A4 polymorphisms.

Polymorphisms of the CYP3A4 gene (encoding for the CYP3A4 isoenzyme) are thought to alter metabolism speed of phentermine, possibly influencing likelihood of anxiety as a side effect.  Should you experience anxiety when taking Qsymia, you may want to use relaxation exercises to determine whether it improves.  You may also benefit from talking to your doctor about dosage adjustments and/or adjuncts to help combat this anxiety.

Appetite loss: A side effect that most Qsymia users can expect to experience is a reduction in appetite.  The phentermine component of Qsymia is a well-known appetite suppressant, and topiramate is also understood to decrease appetite in many users.  Appetite may be suppressed by increasing levels of certain neurotransmitters such as norepinephrine, epinephrine, and dopamine – but also by modulation of activity within the hypothalamus.

The loss of appetite that you may experience as a side effect should help you restrict caloric intake and make better food choices.  Most users will not perceive appetite loss as problematic because they realize it’ll help them lose weight.  However, if your appetite loss becomes so severe that you become malnourished and/or find it difficult to eat much of anything – this may be unhealthy.

It may also be unhealthy if your appetite loss is so extreme, that you lose too much weight at too rapid of a pace.  Talk to your doctor if the change in your appetite is so extreme that you perceive it as being hazardous to your health.  Sometimes a simple dosage reduction may increase your appetite just enough so that you are able to eat enough nutrient-dense foods to avoid malnourishment.

Birth defects: Pregnant women should be cognizant of the fact that the topiramate component of Qsymia is classified as a teratogenic agent, meaning it can detrimentally affect fetal development.  Newborns of women taking topiramate during pregnancy are at approximately 16-fold greater risk for oral birth defects such as cleft lip and cleft palate – compared to others.  Medical literature recommends that pregnant women discontinue Qsymia to decrease risk of birth defects.

Furthermore, nursing mothers should beware that Qsymia may be ingested by newborns via breast milk.  Due to the lack of information regarding risks of Qsymia ingestion among babies via breast milk, it is best for all nursing women to err on the side of caution by abstaining from treatment.  Work with a medical professional to discontinue Qsymia if you are pregnant, as abrupt discontinuation may result in severe adverse events (e.g. seizures).

Blurred vision: A fairly common side effect that is reported among those taking Qsymia is blurred vision.  The blurred vision may occur intermittently in that you notice everything appears slightly blurred for an hour or two, then shifts back to normal.  You may realize that the blurriness is unpredictable in that you cannot predict when it occurs or you may find that blurriness occurs in a predictable manner each day (e.g. 3 hours after you took your dose).

Since there’s a risk of Qsymia causing glaucoma, it may be a good idea to consult an ophthalmologist if you are concerned that the drug may be damaging your eyesight.  An ophthalmologist should be able to accurately assess your vision and rule out any abnormalities.  Assuming you aren’t developing glaucoma and a professional doesn’t believe the drug is damaging your eyes – you may still wonder why your vision is blurred.

The drug may be altering activity in the visual processing centers of your brain and/or neurotransmitter concentrations that affect visual perception.  This may lead to suboptimal visual perception and cause a bit of anxiety.  Should the blurred vision become problematic as to interfere with your driving, work performance, or exercise – your doctor may adjust your dose or recommend trying a different medication.

Body temperature changes: When taking Qsymia, some users will notice changes in body temperature.  In some cases, body temperature changes may be related to a drug-related allergic, resulting in the onset of a low-grade [or possibly high] fever.  Documentation recommends that all Qsymia users be monitored for decreased in sweating or sweat production and/or fever – especially in hot temperatures, as this may require hospitalization.

Not everyone who experiences a change in body temperature during treatment with Qsymia is having an allergic reaction.  Fluctuations in body temperature may be related to changes in neurotransmitter concentrations (e.g. norepinephrine, epinephrine, dopamine) as induced by the drug.  It is understood that a myriad of neurotransmitter systems are implicated in thermoregulatory processes, possibly contributing to any abnormal feelings of warmth and/or coolness that you experience.

For some users, the body temperature changes may be transient and best described as “hot flashes” and/or “cold flashes.”  Though most individuals may be able to cope with mild changes in body temperature, a doctor should be notified to rule out other, potentially serious medical causes.

Furthermore, users of Qsymia may want to consider whether they are losing weight too quickly and/or suffering from micronutrient deficiencies – as these could each alter body temperature.  Work with your doctor to test for micronutrient deficiencies to ensure that they aren’t causing your increased/decreased temperature.  In some cases, reduction in Qsymia dosing may decrease noticeable body temperature changes, but if changes in temperature are disconcerting to the user – discontinuation may be the best option.

Brain fog: Don’t be surprised if while taking Qsymia, you cannot think as clearly as before.  This unclear thinking, commonly referred to as “brain fog” may leave you feeling as if your head is up in the clouds or as if you’ve transformed into some sort of spaced out zombie.  Although it cannot be confirmed, the brain fog is likely caused by the topiramate component of the drug exerting an effect upon voltage-gated sodium channels, calcium channels, and GABA-A receptor activation.

It is also reasonable to suspect that the cumulative effect of topiramate plus phentermine is jumbling your neurochemistry to such an extent, that it’s difficult to maintain mental clarity.  In some cases, the brain fog experienced from Qsymia may occur only during the first few weeks of treatment and subside as your neurochemistry adjusts to its effect.  However, if the brain fog doesn’t abate and interferes with your livelihood, communication skills, and problem solving – you may want to discuss this with your doctor.

Cognitive deficits: It is known that while taking Qsymia, some individuals experience cognitive deficits as a side effect.  When considering that the topiramate constituent is associated with cognitive deficits, it is reasonable to suspect that this side effect may occur among Qsymia users.  Although phentermine may counterbalance some of the inhibitory effect of topiramate, it may be insufficient (in some cases) to reverse the topiramate-induced cognitive deficits.

Another possible explanation is that the cumulative modulation of neurotransmission and arousal as a result of Qsymia causes cognitive deficits in some users.  If you suddenly find it difficult to concentrate, are struggling to retrieve memories, and/or are unable to learn new information during treatment – Qsymia may be the culprit.  Cognitive deficits may also be described as: disorganized thinking, poor problem solving skills, and/or inability to think critically.

The cognitive deficits experienced during treatment may be especially problematic for students and professionals assigned frequent cognitively-demanding tasks.  Should Qsymia interfere with your school and/or work performance by compromising cognitive function, you may need to consider discontinuation and/or alternative interventions.  Alternatively, you may want to work with your doctor to determine whether a slight dosage adjustment could reduce cognitive deficits as a side effect.

Constipation: Another commonly reported side effect of Qsymia is constipation.  The constipation experienced as a side effect may be accompanied by an upset stomach and/or other gastrointestinal issues.  If you end up with frequent constipation from Qsymia, realize that it could be nothing more than a transient side effect in that it subsides with continued treatment and/or further dosage adjustments.

Also consider that constipation induced by Qsymia may be exacerbated by lack of exercise, suboptimal hydration, or inadequate intake of dietary fiber.  You may find that simply increasing physical activity, staying hydrated, and/or increasing fiber intake – reduces some of the Qsymia-induced constipation.  However, if the constipation becomes severe, you may also want to talk to your doctor about taking a safe adjunctive laxative to stimulate bowel movements.

Depersonalization: Qsymia is a drug that alters a myriad of neurotransmitters and physiological arousal.  It is logical to suspect that some individuals may report depersonalization or feeling unlike their normal selves as a side effect.  If you feel like a zombie, are behaving differently than usual, and your thoughts are unpredictable and/or uncharacteristic of your pre-Qsymia self – the modulation of your neurotransmitters is likely the cause.

To ease any depersonalization that you experience, it may be helpful to work with your doctor to decrease your dosage.  The higher the dosage you’re taking, the greater the neuromodulation taking place, and less you should expect to feel like your normal self.  If the depersonalization isn’t severe, you may be able to put up with it as a sacrifice necessary for weight loss.

Some individuals have reported feeling satisfied with the weight loss from Qsymia, but were unable to continue treatment because they felt extremely “weird” while undergoing treatment.  If the depersonalization is too difficult to bear, talk to your doctor about discontinuation of the medication and/or other options.  Also realize that depersonalization may be exacerbated by high levels of anxiety during treatment.

Depression: A side effect that occurs in a small percentage of individuals taking Qsymia is depression.  If you become depressed during your treatment, it is important to discuss it with your doctor as soon as possible.  Though Qsymia-induced depression may be of mild severity and/or transient for some, in others the depression may become extreme enough to provoke suicidal thoughts.

Risk of depression as a side effect may be heightened among users with a preexisting neuropsychiatric disorder.  Still, even if you don’t have a history of psychiatric disorders, it is possible to become depressed during treatment.  This depression may be related to alteration of neuromodulators such as: norepinephrine, epinephrine, dopamine, serotonin, etc.

Among long-term users, depression may be associated with tolerance to Qsymia and a downregulation in endogenous production of norepinephrine and dopamine.  Furthermore, densities of neurotransmitter receptor sites may be deleteriously impacted by the initial supraphysiological concentrations of catecholamines generated in early stages (first few months) of treatment – causing you to feel depressed.  Moreover, one should consider that insufficient caloric intake and/or nutritional deficiencies that may occur during treatment and/or weight loss – could also explain depression as a side effect.

Diarrhea: It is estimated that between 5% and 7% of Qsymia users will experience diarrhea a.k.a. “disaster pants” as a side effect.  The diarrhea may be a result of the phentermine component, the topiramate component, or both chemicals irritating the lining of your gastrointestinal tract.  Irritation of the gastrointestinal tract may expedite gastric motility (the digestion and movement of food through your body), resulting in diarrhea.

The diarrhea may be accompanied by other side effects such as flatulence, indigestion, and upset stomach.  Some individuals may find that diarrhea subsides over time as their body adapts to the effects of Qsymia.  However, if the diarrhea is persistent and doesn’t seem to diminish after several weeks of treatment, it should be discussed with your doctor.

Diarrhea may interfere with nutrient absorption, cause dehydration, and/or lead to unhealthy weight loss as a result of a laxative effect.  If you’re experiencing diarrhea during Qsymia treatment, drinking plenty of water should help you avoid dehydration.  You may also want to stay away from high-fiber foods as these may exacerbate preexisting diarrhea.  A professional may recommend adjusting your dose, switching medications, or using an adjunctive over-the-counter antidiarrheal agent such as Imodium.

Dizziness: Don’t be surprised if, while taking Qsymia, you feel dizzier than usual.  Dizziness is reported as being among the most common side effects.  It isn’t known exactly how Qsymia makes some users feel dizzy, but it could be speculated that the simultaneous alterations in physiology and/or neurobiology contribute.

Qsymia alters concentrations of neurotransmitters such as norepinephrine, dopamine, serotonin, and GABA – and this cumulative modulation may explain the dizziness that you experience.  Dizziness may be most noticeable when a person commences treatment, and may diminish over time as their brain and body adapt to the effect of the drug.  It also could be that Qsymia causes disequilibrium by altering cerebral blood flow, resulting in dizziness.

Those that experience anxiety while taking Qsymia may become dizzy from the anxiety rather than the drug itself.  Another possible explanation for dizziness could be a sudden reduction in caloric intake as a result of treatment.  Anytime a person cuts significant calories and/or loses weight too quickly may induce dizziness.

Dry mouth: It is common for those taking Qsymia to experience dry mouth as a treatment-related side effect.  Though the topiramate component of Qsymia may be the cause of dry mouth in a small number of patients, the most likely cause of dry mouth is the phentermine constituent.  Phentermine is understood to interfere with the ability of the salivary glands to secrete saliva, resulting in xerostomia (dry mouth).

Though a bit of dry mouth may not be perceived as problematic, chronic dry mouth can lead to more serious problems.  Some individuals may end up with dry mouth-induced halitosis, tooth decay, even oral abscesses from insufficient salivary secretion.  This is primarily due to the fact that pathogenic bacteria proliferate and thrive without saliva production, damaging the insides of your mouth.

To combat the dry mouth you’re experiencing from Qsymia, consider chewing sugar-free gum, increasing your water intake, and/or avoiding other stimulants such as caffeine.  You may also want to ask your doctor about using an over-the-counter drug specifically for decreasing dry mouth.  If you’re lucky, you may be able to figure out a way to counteract the side effect of xerostomia, or at least reduce it.

Fatigue: A low percentage (3%) of those taking Qsymia will report fatigue and/or lethargy.  The fatigue may be an unwanted side effect in that it may interfere with conventional weight loss efforts such as exercise.  If you’re fatigued all the time from your medication, it may be difficult to push yourself to go for a jog, lift some weights, or keep active.

Instead, you may feel like doing nothing other than resting on a chair and/or remaining sedentary.  It is possible that the fatigue you’re experiencing is transient and will subside with continued treatment – especially if you are a new user.  On the other hand, the fatigue may be a result of the dosage that you’re taking, and a dosage adjustment may increase your energy level.

Ensure that you’re getting a good night’s sleep, as poor or insufficient sleep [as caused by the drug] may interfere with your energy.  Ask your doctor about ways in which you can deal with the lethargy induced by Qsymia.  He/she may recommend a bit of extra caffeine in the morning, adhering to a strict sleep schedule, or taking an adjunctive drug/supplement for energy.  Also reflect upon whether you have any micronutrient deficiencies and/or health issues that may be the cause of your fatigue [as opposed to the drug].

Glaucoma: A rare adverse effect that may occur in a subset of those taking Qsymia is secondary angle-closure glaucoma.  Glaucoma is a serious condition characterized by intraocular pressure that damages the optic nerve.  Cumulative damage to the optic nerve (as occurs in glaucoma) impairs the ability of the eyes to transmit accurate signals of images to the brain, ultimately leading to permanent blindness.

The likelihood of experiencing glaucoma is considered extremely low, but it has been reported.  Should you suspect that Qsymia is causing glaucoma, it would be recommended to consult an ophthalmologist for a thorough examination.  Keep in mind that a host of other visual related side effects may occur throughout treatment with Qsymia such as blurred vision, myopia, and/or double vision.

If you notice heightened pressure around your eyes or feel as if the drug is affecting your vision, discuss these effects immediately with your doctor.  You may need to discontinue Qsymia if your doctor suspects that the drug is provoking glaucoma.  Should your drug-induced glaucoma become severe, you may need to undergo a laser peripheral iridotomy.

Hair loss: An adverse reaction that may be underreported in the medical literature is hair loss and/or hair thinning as a result of Qsymia.  An unlucky subset of Qsymia users (~3.7%) end up losing hair or notice severe hair thinning after several months of treatment.  This hair loss may become so extreme that a user decides to discontinue treatment because they’d rather have a full head of hair than weight loss.

Men with short hair may find hair loss as a side effect to be less disconcerting than women with a full head of long hair.  Hair loss from Qsymia may be caused by damage to hair follicles from ingesting a combination of exogenous chemicals (phentermine and topiramate).  It also could be that hair loss is related to a combination of hormonal changes and/or nutritional deficiencies (from insufficient caloric intake related to appetite reduction) during treatment with Qsymia.

Some individuals may find that eating a nutrient-dense diet along and/or taking certain supplements can help offset drug-induced hair loss.  Talk to your doctor if you’re experiencing hair loss from Qsymia and determine what can be done.  A dosage reduction may result in some hair regrowth.  Fortunately, if you lose a bit of hair during treatment, you should be able to regrow it upon Qsymia discontinuation.

Headache: Around 10% of Qsymia users will experience headaches as a side effect of the medication.  The severity of these headaches will likely be subject to variation based on the dosage of the drug taken, as well as the particular person experiencing them.  Headaches may be caused by vasoconstriction of intracranial blood vessels from phentermine-induced norepinephrine release.

Headaches can also be caused by insufficient caloric intake, extended periods of fasting, and/or overexerting yourself during exercise.  Furthermore, some individuals may not experience headaches directly from the Qsymia per se, but instead as a result of other drug-induced side effects such as anxiety and/or insomnia.  Those that experience headaches as a result of anxiety and/or insomnia may find that counteractive measures [for anxiety and insomnia] may alleviate the headaches.

If headaches are intermittent and/or mild, you may be able to put up with them throughout your treatment.  However, if headaches become severe and are interfering with your ability to function, you should talk to your doctor.  You may be able to decrease the frequency and/or intensity of your headache with a dosage reduction, over-the-counter headache relief agent, or by ensuring that you’re staying hydrated.

Hypokalemia: A rare adverse reaction that may occur in up to 2.5% of those taking Qsymia is hypokalemia or a deficiency in potassium within the bloodstream.  Those taking the lowest possible dose of Qsymia are less at risk of experiencing this side effect than higher-dose users.  Should you develop hypokalemia during treatment, you will likely experience multiple symptoms such as: constipation, fatigue, muscle cramps, and weakness.

A doctor will be able to tell you whether your blood potassium concentrations moved outside of the normative range (between 3.6 and 5.2 mmol/L).  Should your blood potassium levels dip below 2.5 mmol/L, immediate medical care is necessary as this could be life-threatening.  The cause of Qsymia-induced hypokalemia isn’t clear, but it may be related to other side effects of treatment such as dehydration, diarrhea, and/or vomiting.

Hypokalemia could also be related to insufficient intake of dietary potassium coupled with frequent urination.  Your doctor may make an adjustment to your dosage or recommend discontinuing Qsymia if hypokalemia is suspected.  To reverse hypokalemia, a professional will aim to decrease potassium loss, replenish potassium stores (through supplementation and/or diet), evaluate for toxicities, and make recommendations to prevent future bouts of hypokalemia.

Increased heart rate: Anytime a person ingests a psychostimulant such as phentermine, heart rate may markedly increase.  Although the topiramate component of Qsymia is thought to offset a portion of the stimulatory effect elicited by phentermine, the degree to which it offsets phentermine may be lesser at high doses.  High doses of phentermine will increase peripheral concentrations of norepinephrine and epinephrine, thereby bolstering sympathetic nervous system activation to cause a rapid heart rate.

If your heart is beating much faster than usual, realize that the phentermine component is the likely culprit.  Another possible mechanism by which phentermine within Qsymia may affect your heart rate is by constricting peripheral blood vessels.  Though there’s a chance that the increased heart rate is benign, you should always rule out adverse cardiac events with a cardiologist.  If you have a history of cardiac abnormalities or are at increased risk for adverse cardiac events, Qsymia may be contraindicated.

A way by which you may be able to combat the excessive elevations in heart rate are by taking lower doses of Qsymia.  Lower doses deliver less phentermine and reduce the degree of sympathetic activation and peripheral vasoconstriction.  Be sure to regularly monitor your heart rate while taking Qsymia to ensure that it stays within a healthy range.  Understand that cardio exercise (e.g. going for a long run) could exacerbate heart rate increases induced by the medication.

Indigestion: Up to 3% of individuals taking Qsymia will experience indigestion as a side effect of treatment.  Indigestion is defined as pain or discomfort within the stomach as a result of suboptimal food digestion and/or constipation.  If you just began Qsymia and are experiencing indigestion, realize that it may improve after several weeks of regular usage as your body acclimates itself to the drug.

On the other hand, if indigestion is persistent and/or debilitating, it is important to make your doctor aware of this side effect.  Often times an adjunctive over-the-counter drug or pharmaceutical medication can combat this side effect.  To minimize your chances of indigestion, avoid eating within several hours of going to bed, and engage in some sort of light physical activity (e.g. walking) immediately after eating [as opposed to sitting down].

Additionally, it should be recommended to avoid drinking alcohol and/or smoking – as each of these activities may exacerbate indigestion.  Some believe that eating too much food at a rapid pace can cause indigestion, so make a conscious effort to slow down while eating and see if it helps.  Decreasing consumption of high-fat foods and including more fibrous foods may enhance digestive processes and reduce your chances of indigestion as a side effect.

Insomnia: Insomnia, or the inability to fall asleep and/or stay asleep throughout the night, may occur as a side effect of Qsymia.  The phentermine component of Qsymia functions as a psychostimulant and is likely to interfere with a person’s circadian rhythm.  Without the drug, you may feel drowsier towards the end of the day and/or evening as a result your body endogenously downshifting its arousal to prepare for sleep.

Upon ingestion of Qsymia, your body may be unable to downshift its arousal, and instead may feel highly energized and/or stimulated.  Psychostimulants like phentermine within Qsymia increase production of beta waves (neuroelectrical activity) and inhibit production of alpha waves and/or theta waves – each of which are implicated in sleep.  If you find your sleep suffering as a result of treatment, you may want to talk to your doctor.

Perhaps a dosage reduction would prove beneficial as a result of decreasing phentermine, and correspondingly, the extent to which it increases arousal.  Another option would be to be sure that you’re taking Qsymia early in the morning – to avoid a jolt of phentermine in the evening.  Realize that in some Qsymia users, the topiramate may be equally as problematic as the phentermine for interfering with sleep.

The cumulative modulation of neurotransmitters can sometimes disrupt endogenous neurobiological processes to such an extent, that sleep is deleteriously impacted.  If you are a new user, you may notice that your body eventually adapts to the effects of Qsymia and that your sleep improves with time.  Practicing relaxation exercises before bed, listening to something soothing, and/or asking your doctor for a safe adjunct hypnotic may also prove helpful.

Irritability: Drugs that increase catecholamine concentrations have potential to make some individuals feel irritable.  The phentermine constituent within Qsymia is known to significantly enhance catecholamine concentrations (norepinephrine, epinephrine, dopamine), which in turn activate the sympathetic nervous system.  This engages a person’s freeze-fight-flight response, often resulting in significant irritability.

If while taking Qsymia you flip out or “snap” at little things that previously never bothered you, chances are good that this is related to an overactive sympathetic nervous system.  It should also be considered that since Qsymia may interfere with your ability to get enough quality sleep, the lack of sleep (as induced by treatment) may also be reason as to why you’ve become irritable.  Though the stimulatory effect provided by the drug may be necessary for weight loss, the irritability may be unpleasant to cope with.

You may end up damaging relationships from the excessive irritability.  With a conscious effort of adjunctive relaxation exercises and focusing on improving your sleep, irritability may be minimized.  A slight dosage reduction may also decrease catecholamine concentrations and thus lower your irritability level.  Nevertheless, most individuals would rather have peace of mind and be overweight than bouts of chronic irritability.  If the irritability becomes overwhelming, talk to your doctor about ways by which it can be reduced (e.g. switch medications, adjunctive agents, discontinuation, etc.).

Memory impairment: Among the more debilitating cognitive deficits that may occur during treatment with Qsymia is memory impairment.  You may realize that the drug interferes with your ability to retrieve already-stored memories, as well as with the formation of new memories.  Evidence suggests that up to 11.2% users could experience memory loss as a Qsymia side effect.

Most speculate that topiramate within Qsymia is the cause of memory dysfunction due to the fact that it modulates the neurotransmission of GABA (gamma-aminobutyric acid), a neurotransmitter implicated in memory.  Any memory impairment experienced from this drug could be especially problematic if it affects your ability to perform cognitively-demanding occupational and/or academic tasks.  Poor memory in school or on-the-job may result in suboptimal performance and may get a person fired from his/her job.

For some, a reduction in Qsymia dosage will prove helpful for improving certain aspects of memory.  In other cases, the memory impairment may be an ongoing unwanted effect that fails to subside during treatment.  Talk to your doctor if Qsymia detrimentally affects your memory and inquire about alternative solutions that may be less likely to affect cognitive function.

Metabolic acidosis: A rare adverse reaction that may occur in a small percentage of patients taking Qsymia is metabolic acidosis.  This is a condition characterized by excessive production of acid or suboptimal removal of acid by the kidneys.  If you experience metabolic acidosis, you may experience rapid breathing, confusion, and/or lethargy.

In extreme cases, metabolic acidosis could lead to shock and/or death, whereas in others, the condition may be ongoing and/or mild.  Should you suspect that you’re experiencing metabolic acidosis, it is recommended to consult your doctor for an evaluation. The manufacturer recommends that if metabolic acidosis develops, the dosage should be reduced, and if persistent – the drug should be discontinued altogether.

Mood swings: It shouldn’t be too surprising to experience mood swings while taking Qsymia.  One day you may feel angry or irritable, the next day you may feel happier, and thereafter you may experience a bout of depression.  This drug affects a host of neurotransmitter systems including: norepinephrine, dopamine, serotonin, and GABA – to name a few.

Modulation of these neurotransmitter systems may cause unwanted mood changes, especially among those with neuropsychiatric disorders.  While most would speculate that the topiramate component stabilizes mood and the phentermine component uplifts mood – these are broad generalizations that do not apply to everyone.  Furthermore, the mood enhancement provided by phentermine may wear off after several weeks (similar to as occurs with amphetamine).

Mood swings may be most noticeable during the first few weeks of treatment due to the fact that your brain is adjusting to a myriad of neurochemical alterations (from the drug).  If you’ve been taking Qsymia for an extended duration, your mood may be different than when you originally started – this is because the brain adjusts to drugs over time.  Though modest mood swings may be manageable, if they are disrupting your relationships or wellbeing – you may want to consider a different medication.

Muscle pain: Taking Qsymia could lead to mild-to-moderate muscle pain in a small percentage of users.  The exact causes of the muscle pain resulting from the drug are unclear.  Some believe that perceived muscle pain may be related to anxiety, stress, and/or tension associated with increased activation of the sympathetic nervous system [as induced by the phentermine component].  Although muscle pain may occur throughout your entire body, it has been most commonly reported in the back.

Individuals with chronic back pain (as may be common among those who are overweight and/or obese) may find that the pain amplification from Qsymia is unbearable.  If the pain becomes excruciating, you’ll probably need to ask your doctor about alternative weight loss medications.  On the other hand, if the muscle pain you’re experiencing is minor, your doctor may be able to recommend some safe adjunctive agents (e.g. NSAIDs) to help you cope with the mild pain.

Nausea: Between 3% and 7% of individuals taking Qsymia may experience nausea as a side effect.  A bit of mild nausea may be manageable for most individuals, but if the nausea becomes extreme, it could provoke vomiting.  Understand that nausea is somewhat complex as a side effect in that it can have many causes.

Some users may feel nauseous as a result of medication-induced side effects such as: anxiety, constipation, and/or dizziness.  Others may feel nauseous when they first start taking Qsymia because their physiology is still adjusting to the drug.  Among these individuals, nausea may significantly diminish after several weeks.

Realize that you may feel somewhat nauseous if you are losing weight too quickly or aren’t eating a balanced diet.  Anyone experiencing nausea should notify their doctor and ask whether anything can be done to counteract the nauseous feeling.  Your doctor may advise a dosage reduction and/or an adjunctive antiemetic agent to help you cope.

Numbness sensations: Just under 4% of users may experience hypoesthesia or a reduced sensitivity to tactile sensory stimuli.  Internally, it may feel as if certain parts of your body, or a particular region has become numb.  Numbness sensations may be transient and may occur in “waves” or may be ongoing for an extended duration.

Additionally, any numbness you experience may also be accompanied by tingling sensations (pins and needles).  It isn’t known why Qsymia causes numbness in some individuals, but the feeling may be related to changes in peripheral blood flow.  Phentermine (within Qsymia) stimulates the peripheral release of norepinephrine and epinephrine, which constricts blood vessels.

The constriction of peripheral blood vessels may significantly reduce blood flow to particular regions, ultimately leading you to feel abnormally numb.  Finding ways to increase blood flow to regions that feel numb, should reverse it.  If the numbness becomes unbearable, you may want to work with your doctor to determine whether a slight reduction in dosing could decrease it.

Palpitations: As was noted, the phentermine within Qsymia increases activation of the sympathetic nervous system.  This increased sympathetic activation [as a result of catecholamine release] may cause the side effect of heart palpitations.  Palpitations are classified as rapid, irregular, and/or strong heartbeats that are associated with anxiety.

Heart palpitations are associated with anxiety because they can both cause, and be caused by anxiety.  If you haven’t ever experienced a palpitation, you may freak out thinking that your heart was somehow damaged and/or suspect that you may have a heart attack.  Your anxious meltdown may worsen the palpitations.

To be on the safe side, if you notice palpitations, it is recommended to have your doctor and/or a cardiologist rule out serious cardiac complications.  Assuming your doctor says that you aren’t at risk for adverse cardiac events, you may need to learn some coping strategies if you plan on continuing Qsymia.  To cope with palpitations, it may help to acknowledge them, accept them, and relax – rather than trying to fight them.

Taking proactive steps to reduce your anxiety level such as deep breathing, meditation, or even going for a walk – may decrease the occurrence of palpitations.  For those that are exceptionally perturbed by the palpitations, a reduction in Qsymia dosage may be helpful.  Also, consider asking your doctor whether there’s a safe adjunctive agent that can be taken to mitigate anxiety and/or palpitations from Qsymia.

Skin rash: Estimates suggest that up to 2.6% of individuals taking Qsymia could develop a skin rash.  The skin rash may be characterized by patches of redness, red bumps, and/or itchiness.  For some, the rash may be isolated to a specific region of the body, yet for others it may be widespread throughout the entire body.

The rash could be a sign of an allergic reaction to Qsymia, especially if accompanied by swelling, dizziness, nausea, and/or vomiting.  As soon as you notice a rash, it is important to get in touch with your doctor or a dermatologist for an evaluation.  If you are experiencing an allergic reaction, discontinuation of Qsymia will likely be necessary.

In other cases, a rash that occurs during Qsymia treatment may be related to increased sensitivity of skin to sun exposure.  The phentermine component is understood to increase skin sensitivity to sunlight, and prolonged periods of sun exposure may provoke a wicked rash.  Some have claimed that Epsom salts in a bath can mitigate some of the itchiness of a rash.

Others believe that taking antihistaminergics will help them cope with the rash, however, these are usually not recommended.  Antihistamine drugs may reduce some itchiness, but may also interact with Qsymia and should never be taken without a doctor’s approval.  Furthermore, since antihistamines may cause dementia, it may be best to find a new weight loss drug if you end up itchy from Qsymia.

Sleep disturbances: You may struggle to get a good night’s sleep while taking Qsymia for multiple reasons.  The drug tweaks your neurotransmitter concentrations, which in turn affects arousal, brain waves, and circadian rhythm.  The phentermine within Qsymia promotes the release of norepinephrine, as well as epinephrine – each of which may enhance arousal so significantly, that your body is unable to transition from wakefulness to a sleep.

Even if while taking Qsymia you don’t experience insomnia before falling asleep, you may notice that: you toss and turn throughout the night, wake up several times during the middle of the night, and/or wake up each morning feeling extremely groggy.  This may be due to the fact that the drug affected your sleep cycles, as well as the amount of REM (rapid eye movement) sleep you get each night.  To accurately determine how Qsymia is affecting your sleep, you may want to consult a sleep specialist.

A sleep specialist will be able to test your sleep without the drug, as well as after taking Qsymia and monitor changes.  If changes to your sleep are considered unhealthy and/or extreme by a sleep specialist, you may need to lower your dosage of Qsymia, switch to a different medication, or use an adjunctive medication to improve your sleep.  Also keep in mind that some sleep disturbances may only occur when you first begin taking Qsymia and may subside as your neurochemistry and circadian rhythm adjust to the drug (e.g. after a month).

Sleepiness: Up to 3.2% of those taking Qsymia report experiencing somnolence as a side effect.  Since the phentermine component of Qsymia is understood to act as a psychostimulant by increasing catecholamine concentrations, it is unlikely that phentermine is the cause of sleepiness – especially while it is active.  It is reasonable to speculate that once the phentermine “wears off” (after each dose), a user may experience extreme drowsiness, fatigue, and/or sleepiness – as the result of a “crash.”

Many individuals experience a significant crash after taking psychostimulants.  If you feel extreme sleepiness in between your Qsymia dosages, it may be that the phentermine component is the actual cause.  On the other hand, topiramate can make some individuals feel sedated, tired, and sleepier than usual.  It could be that, for certain users, the topiramate component is overpowering the phentermine to such an extent, that sleepiness ensues.

Hypothetically, somnolence could also be induced by topiramate, and exacerbated by a phentermine-related crash (later in the day), and this may be more pronounced at higher dosages.  Furthermore, if the Qsymia is causing such extreme anxiety and/or heightened arousal, that it affects your sleep quality and/or quantity – you may want to consider that the lack of sleep may be to blame for somnolence as a side effect.

To reverse somnolence, you may want to talk to your doctor about safe adjuncts that may enhance your wakefulness – that aren’t contraindicated with Qsymia.  You may also want to ask about possible agents to enhance sleep quality if suboptimal sleep is to blame for your tiredness.  If the somnolence is excessive, you may need a dosage adjustment or to stop treatment, especially if it interferes with your ability to operate a motor vehicle, work-related productivity, and/or exercise regimen [for weight loss].

Stomach aches: Qsymia may cause stomach aches in some individuals, possibly as a result of irritating the gastrointestinal tract.  This gastrointestinal tract irritation may expedite movement of food throughout the digestive system, thereby causing stomach aches (and possibly diarrhea).  The drug may also cause constipation and/or indigestion in certain individuals, leading them to experience upset stomach.

To deal with these stomach aches, it is recommended to stay hydrated and engage in modest physical exercise after eating.  Modest physical exercise after eating should help alleviate stomach aches induced by constipation.  On the other hand, if you are experiencing stomach aches related to diarrhea, your doctor may recommend taking an over-the-counter adjunct such as Imodium.

You may want to also consider that stomach aches you experience could be related to losing excessive amounts of weight quickly and/or going for long durations without food.  Those who abstain from food consumption for a long duration (as may occur from drug-induced appetite reduction), could end up with a stomach ache.  In this case, increasing meal frequency may help alleviate some of the hunger-related aches.

Suicidal thoughts: A rare adverse reaction that may occur in select Qsymia users is suicidal thinking and/or behavior.  It should be suspected that those with preexisting neuropsychiatric disorders are at increased risk for suicidality while taking Qsymia.  This may be due to heightened sensitivities in neurotransmitter concentrations and/or possibly related to the fact that they are taking other psychiatric medications.

Nevertheless, even those without neuropsychiatric disorders could become depressed and suicidal as a result of alterations in the neurotransmission of norepinephrine, GABA, dopamine, and serotonin.  Suicidal thoughts may occur upon beginning treatment as the brain is adjusting to Qsymia, or after long-term.  If you experience suicidal thoughts after a long-term of Qsymia usage, it may be a result of ongoing supraphysiological catecholamine levels (e.g. norepinephrine).

To cope with these supraphysiological catecholamine levels, receptor densities shift, and your mood may change.  In any regard, if you ever feel suicidal (like you want to die) while taking Qsymia, seek urgent professional help.  Your doctor may recommend discontinuing the medication and testing another that won’t provoke suicidal thoughts.

Thirstiness: About 2 out of every 100 Qsymia users will experience an increase in thirst during treatment.  It is reasonable to speculate that this increased thirst may be a direct result of drug-induced diarrhea.  Diarrhea is a more common side effect which can dehydrate the body, possibly increasing a person’s thirst.

Another side effect that may be associated with increased thirst is dry mouth.  If you experience dry mouth while taking Qsymia, you may feel thirstier than usual and end up drinking more water to counteract the dryness.  Furthermore, increased thirst may be unrelated to the drug and more related to adjunctive weight loss efforts such as physical exercise.

Feeling thirstier than usual may mean that your body is sweating more frequently and/or requires more water than in the past.  Nonetheless, since excess thirst may also be a sign of medical conditions such as diabetes, and should immediately be discussed with a doctor.  Assuming you don’t have any medical conditions causing your thirst, it should be recommended to stay hydrated with clean water.

Tingling sensations: Approximately 20% of individuals taking the highest dose of Qsymia will experience paresthesia or tingling sensations.  These tingling sensations may be described as “pins and needles” or prickling, and may occur throughout the entire body or in a specific region.  Medically, paresthesia is understood to be caused by pressure on or damage to peripheral nerves.

Knowing that paresthesia occurs mostly among high-dose Qsymia users, we can speculate that it’s due to ingestion of phentermine.  Phentermine is known to constrict peripheral blood vessels, possibly to such an extent that blood flow is reduced to extremities.  Reduction in blood flow may cause you to feel these uncomfortable tingling sensations.

Tingling sensations may also be caused by anxiety experienced while taking Qsymia.  Anxiety can trigger a freeze-fight-flight response, which may alter peripheral blood flow and cause you to tingle.  To decrease the tingling, you may want to ask your doctor about decreasing your dosage and simultaneously address excessive anxiety (via relaxation or an adjunctive agent).

Upper respiratory tract infection: Strikingly, up to 17.5% of patients may experience an upper respiratory tract infection as an adverse reaction to Qsymia.  An upper respiratory tract infection may be triggered directly by the drug, such as in the event of an allergic reaction.  It could also occur if by some chance Qsymia impairs your immune system function, thereby increasing likelihood of viral infection.

You may also want to consider that Qsymia may not directly impair your immune function, rather, it may trigger a stress response (through your sympathetic nervous system).  This stress response may interfere with healthy immune function and impair sleep – each of which could increase susceptibility to infection of the upper respiratory tract.  If you end up with an upper respiratory tract infection, you may notice that it affects the nasal cavities and throat, making it difficult to breathe and/or swallow food.

Other signs of an upper respiratory tract infection include: coughing, sinus pain, sneezing, stuffy nose, and wheezing.  Anyone suspecting a drug-related upper respiratory tract infection from Qsymia necessitates immediate medical evaluation.  A medical professional may recommend discontinuing treatment in favor of another drug, especially if your respiratory issues are severe and/or result from an allergic reaction to Qsymia.

Weight loss: Since most people taking Qsymia are significantly overweight, any weight loss experienced shouldn’t be considered an unfavorable side effect.  If weight loss is gradual, and occurs over a period of months (rather than weeks), it is unlikely to be problematic.  However, if weight loss occurs at a rapid pace such as in a few short weeks of treatment, it could be unsafe and/or compromise the health of an individual.

Most experts suggest that weight loss of around 1-2 pounds per week is relatively safe.  On the other hand, losing larger amounts of weight per week (e.g. 5-10 pounds) may cause complications such as: gout, gallbladder dysfunction, fatigue/lethargy, muscle loss, hypoglycemia, fainting, and/or malnourishment.  Also, extreme weight loss over a short-term is generally unsustainable, especially when fueled primarily by a drug.

If you notice that you’re losing weight at an accelerated pace, talk to your doctor about it to ensure your personal safety.  You may need to reduce your dosage of Qsymia if you’re shedding weight too quickly.  The goal should be to lose a steady amount of weight (e.g. 1-2 pounds per week) with a combination of Qsymia, caloric restriction, and physical exercise.

Note: If you experience any adverse reactions listed above, seek immediate medical attention.  A medical professional is qualified to treat any adverse events and should also help you come up with ways to reduce the severity of your side effects.  Moreover, if you have any specific questions about side effects that you’re experiencing from Qsymia, consult a medical doctor.

Variables that influence Qsymia side effects

There are notable variables that influence the particular Qsymia side effects you’re likely to experience, as well as their respective severities.  Examples of these variables include: dosage of Qsymia you’re taking, co-administered substances, duration of administration, and various individual factors (e.g. genetics, medical conditions, time of administration, etc.).  When contemplating the side effects that you’re likely to experience during treatment, reflect upon the influence of these variables.

  1. Dosage (High vs. Low)

Arguably the most impactful variable upon the side effects that you experience is the Qsymia dosage that you take.  Medical literature suggests that individuals taking the highest possible dosages of Qsymia are more likely to experience side effects and/or adverse events than those taking the lowest dosages.  In short, the likelihood of experiencing side effects is dose-dependent – the larger the dosage of Qsymia that you take, the more side effects you are likely to endure.

What’s more, high dosages are associated with increased side effect severity compared to low doses.  As a hypothetical example, let’s say you experience mild insomnia at the lowest possible dose of Qsymia and your doctor decided to increase your dose to double or triple the previous amount.  After the doubling or tripling, you may notice that your insomnia transforms from being previously “mild” to “severe.”

It should be noted although side effect severity doesn’t always increase with a higher dose, the likelihood is greater. Qsymia is manufactured in 4 dosage increments – with the following amounts of phentermine and topiramate, respectively: 3.75 mg/23 mg, 7.5 mg/46 mg, 11.25 mg/69 mg, and 15 mg/92 mg.  (By doing a little math, it becomes obvious that each tablet is formatted to contain 1 mg of phentermine for every 6.133 mg of topiramate).

Those who are taking the 15 mg/92 mg dose (highest) should expect a greater number of side effects, as well as more severe side effects than if they took the 3.75 mg/23 mg (lowest) dose.  Why do the number and severity of side effects increase at higher dosages?  When higher dosages of Qsymia are ingested, more phentermine and topiramate (the chemical constituents) circulate throughout the body and alter physiological and neurobiological processes.

Since there’s a greater amount of each chemical delivered from the higher dosage (15 mg/92 mg), the potency of the effect is greater upon physiology and neurobiology.  As an example, we would expect 15 mg of phentermine (in the highest dose) to release more norepinephrine than 3.75 mg (in the lowest dose).  Similarly, 92 mg of topiramate (in the highest dose) would affect the user’s GABAergic transmission to a greater extent than 23 mg (in the lowest dose).

Furthermore, since high doses of a drug exert a greater effect upon physiology and neurobiology of the user, we can expect greater disruption in homeostasis.  Since homeostatic functioning may be disrupted to a greater degree following ingestion of a high dose compared to a low dose, and the body always aims to maintain homeostasis, there may be a greater compensatory backlash in attempt to correct exogenously modulated (via Qsymia) processes – resulting in more side effects.  At a lower dose, homeostasis is subject to less substantial disruption, meaning there’s likely to be a less severe compensatory backlash and correspondingly, fewer side effects.

Some may also suspect that side effects may be more likely to occur at higher doses due to the fact that a larger quantity of Qsymia (phentermine / topiramate) necessitates absorption, metabolism, distribution, and elimination.  It is possible that pharmacokinetic processes may be less efficient at high doses than they would at low doses, and the decreased efficiency may theoretically increase the occurrence of some side effects.  In brief summary, expect to endure more side effects at high doses and fewer side effects at low doses.

  1. Co-administered substances

Whether you are using any co-administered substances such as: alcohol, over-the-counter drugs, pharmaceutical medications, and/or supplements – can influence the severity of side effects that you experience from Qsymia.  Some co-administered agents may be contraindicated with Qsymia and will significantly increase your risk of adverse events if taken during treatment.  For example, if you were to take an MAOI (monoamine oxidase inhibitor) concurrently with Qsymia, your odds of experiencing a severe adverse event would be high as usage of MAOIs with Qsymia is contraindicated.

Other substances may not be contraindicated per se, but may alter the pharmacokinetics of Qsymia by affecting speed of phentermine metabolism.  Phentermine is metabolized partly by the isoenzyme CYP3A4, and alterations to its metabolism speed may result in a greater number of side effects, as well as increased side effect severity.  An individual taking a CYP3A4 inducer along with Qsymia will metabolize phentermine at a faster rate than usual, possibly provoking side effects that wouldn’t have otherwise occurred at a normative metabolism speed.

Examples of a few common CYP3A4 inducers include:  Clarithromycin, Cobicistat, Ketoconazole, and Ritonavir.  Conversely, someone taking a CYP3A4 inhibitor with Qsymia may metabolize phentermine slower than average, also provoking side effects that wouldn’t have occurred at a normative metabolism speed.  Examples of some notable CYP3A4 inhibitors include: Butalbital, Capsaicin, Carbamazepine, Modafinil, and St. John’s Wort.

Understand that the side effects that result from poor metabolism of phentermine may differ from those associated with rapid metabolism.  Faster CYP3A4 metabolism speed floods the body with a larger amount of phentermine metabolites quicker, so side effects may be more potent and shorter-lived.  Slower CYP3A4 metabolism speed slows the circulation of phentermine metabolites, but side effects may be less noticeable and longer-lasting.

In addition to side effects from the influence of co-administered substance on pharmacokinetics, it is possible that some substances affect the pharmacodynamics of Qsymia to cause side effects.  Any co-administered substance that affects similar neurotransmitter systems as topiramate and/or phentermine may enhance or negate certain effects of Qsymia.  Co-administered agents that augment the pharmacodynamics of Qsymia may exacerbate certain side effects.

Oppositely, co-administered agents that offset the pharmacodynamics of Qsymia may reduce some side effects.  It should also be considered that various substances may not interact with Qsymia pharmacokinetically or pharmacodynamically, yet still influence side effects.  As an example, let’s assume that you were to experience cognitive dysfunction and drowsiness while taking Qsymia.

If you frequently drink alcohol, the cognitive dysfunction and drowsiness may be worsened from the effect of alcohol.  To flip the script, if you are a regular caffeine drinker, you may not notice the same degree of cognitive dysfunction nor drowsiness due to the fact that caffeine attenuates these side effects.  Finally, you may need to evaluate whether you may have wrongfully attributed certain side effects to Qsymia, when these side effects are actually from a co-administered substance.

  1. Term of administration

How long you’ve been using Qsymia can influence the side effects that you experience.  It isn’t always clear as to whether short-term users, moderate-term users, or long-term users experience more side effects (when compared) – this is likely subject to individual variation.  Short-term users may be more prone to adjustment-related side effects or side effects associated with the body being unaccustomed to Qsymia, whereas long-term users may be more prone to long-term effects (from ongoing influence of the drug over an extended duration).

  • Short-term: A person that’s only taken Qsymia for a few days or weeks may experience some side effects due to the fact that an exogenous substance was recently introduced to their body – and it hasn’t yet adapted. Some individuals may take several months to fully adapt to the effects of Qsymia, and until they’ve adapted, side effects will persist.  For this reason, we can expect that many short-term users will deal with side effects.  That said, many short-term users are taking relatively low doses (compared to moderate and/or long-term users) and may be less likely to experience certain side effects that tend to occur at high doses.
  • Moderate-term: Those that have been taking Qsymia for several months should be fairly well-adjusted to the drug. After several months, many of the adjustment-related side effects that occurred in the early stages of treatment should have diminished in intensity, or stopped entirely.  Additionally, if you’ve stuck with Qsymia for months, your doctor will have had enough time to properly configure your dose to an amount that you can tolerate.  Moderate-term users may also be less likely to experience side effects than long-term users due to the fact that they aren’t yet tolerant to high doses of Qsymia.
  • Long-term: It should be prefaced by speculating that a majority of long-term Qsymia users exhibit favorable tolerability to the drug, otherwise they would’ve discontinued before a “long-term.” A subset of individuals that have used Qsymia for years may experience no unwanted side effects due to the fact that their physiology and neurobiology have long-adapted to the daily administration of the phentermine-topiramate combination.  On the other hand, some long-term users may also experience more severe side effects than short-term or moderate-term users due to the fact that they became tolerant to lower doses of Qsymia, and needed to increase their dosage to the highest available amount.  As is known, the greater the dose a person takes, the more numerous and severe his/her side effects are likely to be.  Long-term users may also experience unwanted long-term side effects resulting from changes to physiology and neurobiology that accumulate over an extended period of time.
  1. Individual Factors

Hypothetically, two individuals may commence Qsymia treatment on the same day, at the same dose, and avoid using co-administered substances.  Knowing that dosage and duration are equivalent, as well as that neither individual is using other substances with Qsymia, we would predict that side effects should be relatively similar.  However, it may turn out that side effects may differ significantly between the two users – one may report mild insomnia, and the other may experience severe hair loss, depression, and diarrhea.

What explains the differences in side effects between these two hypothetical users?  Individual factors.  Examples of some prominent individual factors that will likely influence Qsymia side effects include: adjunctive weight loss efforts, body composition, genetics, medical conditions, whether the drug was taken on an empty stomach, as well as the time of administration.

Adjunctive efforts: Qsymia is recommended to be used as part of a multi-faceted weight loss approach involving dietary modification and physical exercise.  A person who is exercising and eating a more nutrient-dense diet may experience fewer side effects from the drug than if that same individual remained sedentary and/or ate junk food.  Sufficient exercise and nutrition can increase energy and enhance cognitive function, possibly offsetting side effects of fatigue and cognitive deficits.

It should also be considered that the type of exercise and/or dietary modifications made could exacerbate certain side effects from Qsymia.  Someone that’s experiencing fatigue as a side effect may end up over-training such as by jogging for hours – hoping that it’ll speed up weight loss.  The reality is that over-training may exacerbate fatigue experienced as a side effect of Qsymia – leading to greater fatigue than if you remained sedentary.

Furthermore, although the drug may curb your appetite, failure to consume sufficient quantities of micronutrients could exacerbate side effects.  Someone who experiences memory loss as a side effect of Qsymia may find that their new diet exacerbates memory impairment.  This may be a result of insufficient intake of various nutrients.

Analyze your adjunctive weight loss efforts and evaluate whether they may be increasing or decreasing side effects.  Are you over-training or consuming an insufficient number of calories to maintain energy? Or are you remaining sedentary and continuing to eat junk foods – rather than nutrient dense foods?  It may be helpful to reflect upon how your adjunctive efforts may exacerbate or attenuate drug-induced side effects.

Age: The age of a person taking Qsymia may influence the side effects that they experience.  Healthy adult user may be less prone to severe side effects than pediatric users or elderly users.  Pediatrics may suffer from severe side effects and/or adverse reactions due to the fact that their nervous systems and/or brains aren’t fully developed, making them more sensitive to the effects of Qsymia (phentermine/topiramate).

Furthermore, it should be suspected that pediatrics who use Qsymia for an extended duration may detrimentally affect their brains’ during a critical developmental period.  Since the brain of a healthy adult user isn’t still developing, long-term complications may be less likely.  The body size of adults is also larger when compared to pediatrics, allowing them to tolerate larger doses of the drug by comparison.

Elderly individuals may not metabolize, distribute, nor excrete Qsymia as efficiently as younger adults, possibly increasing their likelihood of side effects.  It is also known that elderly individuals tend to exhibit declining health, comorbid medical conditions, and are often using other medications.  Hence, elderly Qsymia users may be at risk for more overall side effects as a result of their age.

  • Source: http://www.ncbi.nlm.nih.gov/pubmed/14639056

Body size & composition: A person’s body size and composition may also be implicated in drug-related side effects.  Someone who’s 6 feet tall and weighs 400 lbs. may metabolize, distribute, and excrete a moderate dose of Qsymia (7.5 mg/46 mg) at a different rate than a person who’s 4 feet tall and weighs 300 lbs. The differing rates in metabolism, distribution, and excretion as a result of body size could affect some pharmacokinetic-related side effects, even if to a negligible extent.  Body fat and muscle mass percentages may also influence drug-related pharmacokinetics, possibly resulting in slightly different side effects for someone with high fat/high muscle than someone with high fat/low muscle.

Food intake: A person who takes Qsymia on an empty stomach may experience different side effects than if he/she took it after a large meal, or even a light snack.  Medical documentation suggests that Qsymia can be taken with food or on an empty stomach, but users may notice that certain side effects (e.g. upset stomach) are more/less severe relative to their food consumption.  For example, some users may report an upset stomach if they eat a large meal before their dose.

Others may find that if they eat a large meal before their dose, they don’t experience an upset stomach.  Food intake could affect the absorption speed of Qsymia, as well as other parameters, possibly increasing or decreasing likelihood of certain side effects.  It should also be hypothesized that eating specific types of foods (e.g. healthy fats) while taking Qsymia may attenuate side effects caused by other types of foods (e.g. refined carbohydrates).

The amount of elapsed time since food consumption (prior to taking Qsymia), as well as the amount of time you wait after taking Qsymia to eat food – may impact side effects.  For example, a person may experience the side effect of a stomach ache as a result of: taking Qsymia on an empty stomach [resulting in GI irritation], an extended duration since previous food consumption, as well as no food intake for hours after drug ingestion.  Had this same individual consumed food immediately before taking the drug (or a particular type of food), he/she may not have experienced a stomach ache.

Genetics / Epigenetics: A person’s unique genetic and epigenetic signature may increase or decrease susceptibility to certain side effects.  To state an example, individuals exhibiting polymorphisms of the CYP3A4 gene may metabolize the phentermine constituent of Qsymia at a different pace than those without a CYP3A4 polymorphism, resulting in altered side effects.  Most CYP3A4 polymorphisms result in less efficient, slower metabolism of phentermine – possibly increasing likelihood of certain side effects, while decreasing likelihood of others.

A myriad of other genes that aren’t implicated in pharmacokinetics could still affect how a person responds to Qsymia.  For example, someone with a polymorphism of the norepinephrine transporter (NET) gene may experience a different set of side effects than a person devoid of an NET polymorphism.  Moreover, epigenetic expression may also predict whether someone is more or less prone to drug-related side effects (e.g. anxiety, depression, fatigue, etc.) – disparities in epigenetic biomarkers may explain why 2 identical taking Qsymia experience differing side effects.

Medical conditions: Certain medical conditions may exacerbate or attenuate various side effects experienced while taking Qsymia.  For example, someone with a neuropsychiatric disorder such as major depression may notice that their depressive symptoms become significantly worse as a result of treatment.  This could be due to the fact that they are more sensitive to the modulation of neurochemistry (as occurs with Qsymia), making them more at risk for adverse events like mood swings and suicidality.

Another example of a medical condition that may impact Qsymia side effects is Type 2 diabetes.  Since Qsymia can cause weight loss, and weight loss is associated with drops in blood sugar, users with Type 2 diabetes may be increasingly prone to bouts of hypoglycemia (low blood sugar) during treatment.  Symptoms of hypoglycemia include: anxiety, cognitive impairment, and heart palpitations – all of which are reported side effects of Qsymia.

Therefore, having a comorbid medical condition may not only make it difficult to differentiate symptoms of the specific condition from drug-induced side effects, but certain drug-induced side effects may be exacerbated upon symptomatic worsening of a condition.  Also keep in mind that theoretically, certain medical conditions may attenuate side effects that you would’ve otherwise experienced from Qsymia.

For example, if you were to have a mild case of hypothyroidism (untreated), this condition may cause you to feel fatigued, lethargic, and sleepy.  Since the hypothyroidism hasn’t been properly treated, but you initiated treatment with Qsymia, it is possible that the phentermine component causes a little anxiety.  Had you properly treated the condition before taking Qsymia, it is possible that you may have experienced extreme anxiety as a side effect due to your thyroid levels being within a normal range.

You should also keep in mind that Qsymia could cause or worsen certain medical conditions (e.g. kidney stones), and the worsening of these conditions may cause unwanted side effects.  Before initiating treatment with Qsymia, work with your doctor to rule out any untreated medical conditions.  If you have been diagnosed with a comorbid condition, properly treating it should allow you to know whether you are experiencing side effects of Qsymia, untreated symptoms of a condition, or a disconcerting blend of both.

Sex: It is reasonable to speculate that there may be some modest sex-specific side effects associated with Qsymia treatment.  Males and females generally exhibit distinct sex-specific concentrations of hormones, brain activity, and neurotransmitters.  Though no research has been conducted with the intent of elucidating sex-specific Qsymia side effects, it is possible that the impact of the drug (topiramate / phentermine) on physiology and neurobiology yields side effects contingent upon the user’s sex.

Keep in mind that sex-specific side effects may be difficult to measure and/or document and aren’t frequently analyzed, especially if they are likely to be of negligible importance to the user.  Furthermore, it appears as though the drug promotes similar fat loss regardless of a person’s sex.  However, there’s a chance that women taking Qsymia may have increased odds of experiencing a particular side effect than men and vice-versa.

Sleep / Stress: The side effects of Qsymia that you experience may also be affected by the amount of sleep that you get and/or stress that you’re under.  Someone who isn’t getting enough quality sleep at night may be more susceptible to experience extreme anxiety, cognitive impairment, mood swings, and daytime fatigue during treatment – than if that same individual was regularly getting enough sleep.  Poor sleep induces detrimental changes to epigenetics, physiology, and neurobiology, whereby susceptibility of medication-induced side effects may increase.

Additionally, a person who is chronically stressed may find that Qsymia potentiates their already-existing anxiety, cognitive impairment, and fatigue – compared to someone who leads a low stress lifestyle.  Keep in mind that a modest amount of stress may offset specific side effects that a person may have otherwise experienced such as drowsiness, however, this is subject to individual variation.  Just know that your stress level may be exacerbating unwanted side effects, but could be mitigating others associated with low arousal (e.g. drowsiness).

Time of administration: What time of day do you typically administer Qsymia?  The time of day that you take the drug could impact the side effects that you experience, as well as the degree to which you find certain side effects problematic.  The manufacturers of Qsymia, as well as medical professionals recommend taking the drug in the morning for best results.

However, this does not necessarily mean that all users are following manufacturer guidelines – some users may take the drug in the afternoon or evening.  The time at which you administer Qsymia may yield different side effects based on your circadian rhythm and individual variation. For example, someone who experiences drowsiness from taking Qsymia in the morning may find that if the drug is taken at night, drowsiness is significantly amplified (due to the fact that they were already drowsy from a downshift in arousal as triggered by the circadian rhythm).

On the other hand, this drowsiness at night may perceived as less bothersome than drowsiness experienced during the morning or afternoon because it won’t interfere with cognitively-demanding work tasks.  Oppositely, consider that if Qsymia makes you feel stimulated and/or more anxious than usual, taking it in the morning may help you stay alert, whereas taking it at night may cause insomnia by interfering with your circadian rhythm.  Even slight variations in timing of administration (e.g. 5:00 AM vs. 9:00 AM) may yield slightly different side effects.

Qsymia: Do the therapeutic benefits outweigh the side effects?

If you’ve been taking Qsymia for awhile, it is important to evaluate whether the therapeutic weight loss benefits you experience outweigh the problematic side effects.  The luckiest subset of Qsymia users will experience clinically significant weight loss without any noticeable or severe side effects.  These individuals should be classified as utopian responders in that their health is improving as a result of treatment, and they don’t have any problem tolerating the drug.

The obvious course of action for those who are experiencing all benefits without any side effects is to continue treatment.  Similar to the utopian responders are those who don’t experience any side effects from Qsymia, but may also derive zero weight loss benefit.  If you experience zero unwanted side effects from treatment, yet find that the drug doesn’t help you lose weight – it doesn’t really make much sense to continue spending money on an ineffective treatment.

No matter how well you tolerate the drug, if it isn’t doing its job (helping you lose weight), you may want to talk to your doctor about alternative options and/or discontinuation.  To flip the script entirely from those who experience zero or negligible Qsymia side effects, there are likely a subset of Qsymia users that will experience a cornucopia of disastrous side effects and experience zero weight loss.  In this dystopian scenario of many severe side effects with zero therapeutic benefit, the next logical step is discontinuation of the treatment and/or transitioning to a more tolerable drug.

Most Qsymia users will experience a mix of some therapeutic benefit with side effects.  In this case, it is up to you and your doctor to determine whether the therapeutic benefits you’re attaining from treatment outweigh the side effects enough to justify continued treatment.  If you’re only losing 1 pound every month or two from treatment, and are experiencing moderately severe side effects – cessation of treatment may be your best option.

However, if you’re losing 5-10 lbs. per month and are experiencing a few side effects that you can tolerate – you’ll probably want to continue treatment.  It may be more difficult to know whether to continue or discontinue if you’re losing a fair amount of weight, but the side effects are detrimental to your work performance or social relationships.  To track the ongoing efficacy of the drug in respect to your side effects, you may want to maintain a daily journal of your experience.

Maintaining a journal will help you understand whether side effects diminish and/or improve over time, as well as whether the drug maintains its effectiveness.  Furthermore, since it is difficult to mentally remember every last side effect that you experienced during treatment, if you tracked side effects in a journal, you can easily gloss over your entries to tell your doctor exactly what you experienced.  This big-picture long-term tracking in a journal can be very helpful for deciding whether to continue or discontinue treatment.

Possible ways to reduce Qsymia side effects

If you are experiencing side effects from Qsymia, there may be ways in which they can be mitigated or inhibited.  Various side effect mitigation strategies include things like: dosage adjustments, modifying dosing schedule, utilizing safe adjuncts, and eliminating unnecessary substances (that may provoke interaction effects).  Prior to testing any of these side effect mitigation strategies, the safety and hypothesized efficacy should be verified by a medical professional.

  1. Dosage adjustment: To minimize likelihood of unwanted side effects, it is recommended that all users take the minimal effective dose or the lowest amount necessary to facilitate weight loss. It is documented that there’s a dose-dependent relationship between side effect occurrence and severity. Specifically, the greater the dose a person takes, the more likely they are to experience side effects, as well as side effects of heightened severity.  While decreasing to a lower dose may reduce side effects, in some cases an increase in dose may alleviate side effects that occur only at lower doses.  For example, someone taking a low dose may find that they feel drowsy, whereas once the dose is increased, the same individual may report alertness (due to the increased phentermine).  Work with a medical professional to adjust your Qsymia dosage to find the most tolerable, effective quantity.
  2. Alter dosing schedule: If you take Qsymia every morning and are experiencing unwanted side effects, you may want to ask your doctor whether you could try taking the drug in the early afternoon or evening. Hypothetically, if the drug is making you drowsy and/or interfering with your work performance, maybe taking it in the afternoon wouldn’t interfere as much with your daytime productivity. Oppositely, if you are experiencing insomnia as a side effect from taking the drug in the afternoon, you may want to try taking it very early in the morning and determine whether the insomnia subsides.  Also consider that altering dosing schedule even by a couple of hours may make a difference.  If you take Qsymia at 7:00 AM after you’ve been up for 2 hours, you may want to instead try taking it immediately upon waking at 5:00 AM – or vice-versa to determine whether these micro changes in dosage timing are helpful.
  3. Strict adherence: Are you taking your doses of Qsymia at precisely the same time every day, or are you within 2-3 hours of taking it at the same time each day? The drug is intended to be taken at exactly the same time each day. Failure to administer Qsymia at nearly the exact same time each day could lead certain users to experience mini-withdrawal periods and/or exacerbation of certain side effects.  Strict adherence to a set timing of administration may result in fewer side effects.  Furthermore, accidentally forgetting to take Qsymia or skipping a dose may also provoke unwanted effects.  For this reason, be sure to administer the drug every day unless your doctor instructs otherwise.
  4. Test with food vs. empty stomach: Some Qsymia users will find that they experience fewer side effects such as constipation, diarrhea, nausea, and upset stomach – if they take the drug with food. The medical literature suggests that the drug is safe to take with or without food (on an empty stomach). If you’re experiencing side effects, especially gastrointestinal-related, experiment by taking the drug before a meal, with food, and after a meal to determine whether any unwanted side effects abate.  You may also want to experiment with differing amounts of food, as well as types of food (e.g. high-fat, high-fiber, high-protein, etc.) to determine whether a particular amount and/or type of food leads to fewer side effects.  If you experience side effects every time you take Qsymia with food, you could also test whether these side effects decrease if you take the drug on an empty stomach.
  5. Slow titration phase: Those new to taking Qsymia generally begin treatment on the lowest dose (3.75 mg/23 mg). Thereafter, they generally are titrated upwards to moderate doses of 7.5 mg/46 mg, followed by 11.25 mg/69 mg, and possibly 15 mg/92 mg. In some cases, titrating to a high dose too quickly may increase side effects due to the fact that the body hasn’t had sufficient time to adjust to the drug.  A slower titration phase may allow the body to acclimate itself to the drug over a longer duration, and side effect severity may be lessened [compared to rapid upward titrations].
  6. Adjunctive substances: Individuals that have been taking Qsymia for an extended duration should have a good feel for their most disconcerting side effects. If you’ve been taking the medication for 3 months and notice that the drug makes you feel fatigued throughout the day, you may be able to combat this fatigue with a safe adjunctive agent (e.g. caffeine). Another example could be that you’re experiencing insomnia from the drug, but an adjunct hypnotic may help you sleep better.  Talk to your doctor to determine whether you could reduce certain Qsymia side effects with safe, non-contraindicated adjuncts.
  7. Eliminate substances: If you started taking Qsymia, but regularly use other substances such as: alcohol, caffeine, or over-the-counter drugs – it may be helpful to cease use of these other substances. Your doctor will be able to tell you whether other agents you’re taking are contraindicated and/or could interact with Qsymia. Even if substances you’re using aren’t said to interact with Qsymia, assuming they aren’t medically necessary, you may want to stop using them and determine whether any side effects improve.
  8. Medical evaluation: All individuals should undergo a thorough medical evaluation before starting Qsymia. A medical evaluation will help professionals pinpoint any additional medical conditions that may be affected by Qsymia, as well as whether you should undergo simultaneous treatment for another condition. If left untreated, symptoms of various medical conditions may exacerbate side effects of Qsymia.  For example, assuming Qsymia were to induce fatigue, if a user has untreated hypothyroidism, the fatigue may be more extreme than usual.
  9. Topiramate + Phentermine: Each Qsymia capsule is formatted to include ~6.133 mg of topiramate for every 1 mg of phentermine. Although this is a clinically effective ratio for weight loss based on data from clinical trials, it is unknown as to whether these ratios are optimal for all users. Some individuals may find that slightly more topiramate to phentermine is more tolerable and/or more effective, whereas others may find that less topiramate to phentermine is more tolerable and/or more effective – than the ratio in Qsymia.  Some doctors may want to test prescribing each agent separately in differing ratios and/or adding on slightly more of one agent to determine whether tolerability and/or efficacy improves.
  10. Continued usage: If you’ve only been taking Qsymia for several days or even several weeks, there’s a chance that your body hasn’t fully adjusted to its effects. Since you may not have fully adjusted to the drug, you may still experience unavoidable adjustment-related side effects. For this reason, it may make sense to continue using Qsymia in hopes that your body will adjust itself to the drug.  Once your body has fully adjusted to the ongoing administration of Qsymia, various side effects may subside.

Note: If you’ve tried all of the tactics suggested above for side effect mitigation, you may want to discuss discontinuing Qsymia with your doctor.  Qsymia should never be stopped abruptly due to the fact that withdrawal symptoms can occur, some of which may be severe (e.g. seizures).  Even if your side effects are troubling, don’t attempt to stop treatment on your own without proper medical guidance.

Have you experienced Qsymia side effects?

If you’ve been taking Qsymia, be sure to leave a comment discussing any side effects you’ve experienced.  To help others get a better understanding of your situation, provide some details such as: your Qsymia dosage, how long you’ve been taking it (e.g. 2 months), and whether you’re taking any other substances along with it.  When you began taking Qsymia, how long did it take for you to notice the emergence of treatment related side effects?

Did you notice side effects from your first day of treatment?  Or did it take several weeks before you experienced unwanted effects?  Assuming you’ve dealt with some side effects from Qsymia, which particular side effects are most debilitating and how have they affected your life?  Rate each of your most debilitating side effects on a scale from 1 to 10 (with “1” being least severe and “10” being most severe).

For those that have used Qsymia for an extended duration (months or years), have any side effects either improved OR worsened over time?  If you have any tips or strategies that you use to cope with Qsymia side effects, feel free to document them in your comment.  Understand that while Qsymia is an effective agent for weight loss among those with obesity, the side effects may outweigh the benefits for many users.  Always listen to your body and work closely with your doctor to decide whether Qsymia is worth continuing or discontinuing.

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