Qsymia side effects and how to avoid them

Qsymia is a prescription weight loss pill manufactured by Vivus that combines phentermine and topiramate and is FDA-approved for people 12 years and older.

Phentermine is a controlled substance that reduces appetite, and topiramate is used to treat seizures and mood disorders, but can also reduce binge eating and fat storage.

Qsymia can cause serious side effects like birth defects, heart problems, and an increased risk of addiction.

Qsymia can be a useful tool for weight loss when combined with healthy eating and exercise, but it’s essential to understand its potential side effects. Some may be mild while others can be serious and impact daily life.

This guide will help you learn about the common, serious, and long-term side effects of Qsymia. It will also give you simple tips to manage them and, most importantly, when to seek medical advice.

Learn about the common and serious side effects of Qsymia and how to manage them, including increased heart rate, mood changes, and birth defects.

What is Qsymia, and how does it work?

Qsymia is an FDA-approved weight loss pill that combines two drugs: phentermine and topiramate, to reduce appetite and feelings of hunger.

These two medicines work together to decrease your food cravings and make you feel full faster. Unlike some newer weight loss treatments, Qsymia is a pill, not an injection. However, it can still have side effects you should be aware of.

It’s meant to be used with a low-calorie diet and regular exercise for weight loss in people with obesity or weight-related health conditions.

Qsymia is a combination of phentermine and topiramate (extended-release)

Qsymia is a combination of two medications: phentermine and topiramate (extended-release) to help with weight loss.

• Phentermine: A stimulant that’s an appetite suppressant. You feel less hungry, so you eat less.
• Topiramate extended-release: A medicine used to treat seizures and migraines. Also used to reduce appetite and food cravings so you can stick to a lower-calorie diet.

How it works for weight loss

Qsymia combines two medications that work together to help you eat less:

• Phentermine reduces hunger by stimulating the brain’s appetite control center, so you feel less hungry.
• Topiramate (extended-release) increases feelings of fullness and reduces cravings, so you stop eating when you’re satisfied.

Together, they help you eat fewer calories by reducing appetite and feeling full sooner, which leads to weight loss over time.

Common side effects of Qsymia

Clinical trials show that the most common side effects of Qsymia include:

• Constipation
• Dry mouth
• Numbness and tingling in the skin
• Colds or other upper respiratory infections
• Headache

Other most frequent and common side effects of Qsymia in adults include:

• Trouble sleeping
• Dizziness
• Changes in taste or loss of taste

In children aged 12 and older, common side effects of Qsymia can include:

• Feeling sad or depressed
• Fever
• Flu-like symptoms
• Joint pain
• Sprains
• Dizziness

These side effects were mostly mild to moderate and occurred soon after starting the medicine or increasing the dose. For most people, they went away on their own over time without stopping the medication.

Numbness and tingling in hands/feet

One of the most common side effects of Qsymia is numbness or tingling in your hands, feet, or face. This is uncomfortable but not dangerous. It’s more likely to happen with higher doses and goes away as your body gets used to the medicine.

If the tingling doesn’t go away or gets worse, talk to your doctor. They may lower your dose or prescribe something else.

Dry mouth

Dry mouth is another common side effect of Qsymia. This is because the phentermine in the medicine reduces how much saliva your mouth makes.

To help with dry mouth, drink water often during the day. Chewing sugar-free gum or sucking on sugar-free candy can also help make more saliva. You can also use a saliva substitute if needed.

Dry mouth can lead to tooth decay and gum problems, so make sure to brush and floss daily and keep up with dental checkups.

If dry mouth becomes a problem, tell your doctor. They may be able to adjust your medication to help.

Constipation

Qsymia can cause constipation in some people due to the drying effect of phentermine.

Mild constipation can be managed at home. Eat more fiber-rich foods like fruits, vegetables, and whole grains. Drink plenty of water to help soften your stool and stay active with regular exercise.

If that’s not enough, you can try an over-the-counter stool softener or laxative like docusate. If you need it for more than a week or if the constipation gets worse, talk to your doctor. It’s important to treat constipation early to avoid bigger problems.

Altered taste

While taking Qsymia, you might notice a metallic taste or other changes in how food tastes. This side effect isn’t usually harmful. Some people find it helps them eat less, but others may find it annoying.

While taking Qsymia, you may notice a metallic taste or other changes in how food tastes. This side effect isn’t usually harmful. Some people find it helps them eat less, but others may find it annoying.

If the taste changes bother you, talk to your doctor. They may be able to prescribe another weight loss medication that works better for you.

Insomnia

Trouble sleeping (insomnia) is another possible side effect of Qsymia. This happens because phentermine is a stimulant and can make it harder to fall or stay asleep.

To avoid this, it’s best to take Qsymia early in the morning. Keeping a regular sleep routine and avoiding caffeine or exciting activities in the evening can also help.

If you’re still having trouble sleeping, talk to your doctor. They might lower your dose or recommend a sleep aid.

Dizziness

Dizziness is another common side effect of Qsymia. It’s more likely with higher doses, but usually gets better as your body adjusts to the medicine.

Until you know how Qsymia affects you, avoid driving, operating machinery, or doing tasks that need full attention. Alcohol and some other medicines, like certain allergy pills, can make dizziness worse, so it’s a good idea to limit alcohol and ask your pharmacist before taking anything new with Qsymia.

If the dizziness doesn’t go away or is making daily life hard, talk to your doctor. They can help you find the best way to manage it.

Headache

Headaches are a common side effect of Qsymia and may occur when you first start the medication or when your dose is increased. They can range from mild to moderate and are often caused by changes in your body’s response to the medication, dehydration, or even shifts in blood pressure or sleep patterns. While usually not serious, frequent or intense headaches can interfere with your daily life. Stay hydrated because dehydration is a common headache trigger, especially since Qsymia can cause dry mouth. Drink plenty of water throughout the day to prevent this.

If you do get a headache, over-the-counter (OTC) pain relievers like acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) may help. Check with your doctor or pharmacist first, especially if you have other health conditions or are taking other meds. Getting enough rest and managing stress helps, too, as poor sleep and tension can make headaches worse.

Try deep breathing, meditation, or light stretching to ease the discomfort. Keep track of your headaches, note when they happen, and what might be causing them. This info can help your healthcare provider manage them.

If your headaches are severe, don’t respond to OTC treatment, or are with other symptoms like vision changes, nausea, or confusion, call your doctor. These could be signs of a bigger problem or mean your medication needs to be adjusted.

Cold symptoms

Cold symptoms (stuffy nose, sore throat, cough) occur in a small percentage of people taking Qsymia. These are usually mild and may be related to your body adjusting to the medication.

If you get cold-like symptoms while taking Qsymia, like a stuffy nose, sore throat, or mild cough, get plenty of rest and stay hydrated. Drink water throughout the day and take it easy to feel better.

Over-the-counter remedies like saline nasal sprays, throat lozenges, or mild pain relievers like acetaminophen may also help. Monitor how you feel. If your symptoms get worse or don’t go away after a few days, check with your healthcare provider to rule out an infection or other health issue.

Also, avoid triggers like smoke, dust, or strong odors, which can make symptoms worse. If the cold-like symptoms continue to bother you or interfere with your daily activities, let your doctor know. They may adjust your medication or suggest other ways to manage the symptoms.

Less common side effects

Some less common side effects of Qsymia may occur, but are usually mild. In many cases, they go away on their own as your body adjusts to the medication.

• Trouble with attention or memory
• Joint pain (especially in children)
• Faster heart rate
• Feeling sad or depressed
• Feeling anxious or worried
• Suicidal thoughts or behavior
• Low potassium levels
• Slower growth in children
• Changes in vision
• Too much acid in the blood (metabolic acidosis)
• Kidney problems
• Less sweating (more common in children)
• Skin rashes or reactions

Serious side effects and warnings

Serious side effects of Qsymia can occur in some people. These may include:

• Birth defects (if taken during pregnancy)
• Suicidal thoughts or behavior
• Eye problems, like sudden vision loss or glaucoma
• Kidney problems, such as kidney stones or severe back pain
• Trouble with thinking, memory, focus, or speaking clearly
• Slowed growth in children 12 and older
• High acid levels in the blood (metabolic acidosis)
• High ammonia levels in the blood
• Low potassium levels
• Mood changes, like depression, anxiety, or irritability
• Trouble sleeping
• Fever
• Low sweating in hot weather, which can lead to overheating
• Serious skin reactions, like rashes or blisters (a rare but life-threatening condition)
• Allergic reactions
• Weak or brittle bones
• Seizures if you stop taking Qsymia too quickly
• Increased heart rate

These side effects are not common but can be serious. Always tell your doctor if you notice any unusual symptoms.

Cardiovascular risks

Some people experience a faster heart rate while taking Qsymia. This is because phentermine is a stimulant.

It can be scary if your heart beats faster than normal, but for most people, this side effect is mild and goes away as the body gets used to the medicine. However, if you have heart problems, Qsymia may not be the right choice for you.

Your doctor will likely check your heart rate regularly while you’re on Qsymia. Let them know if your heart keeps racing, especially when you’re resting. They may need to lower your dose.

If you have chest pain or trouble breathing along with a fast heartbeat, get emergency help right away; it could be something more serious.

Mental health effects

Topiramate, one of the medications in Qsymia, may increase the risk of suicidal thoughts. This is a known side effect of all anti-seizure medications. It can happen as early as 1 week after starting Qsymia or later during treatment.

Watch for new or worsening depression, anxiety, agitation, irritability, panic attacks, trouble sleeping, aggression, acting on dangerous impulses, extreme increase in activity/talking (mania).

Get medical help right away if these symptoms occur. Family/caregivers should also be aware.

Pregnancy risks

Qsymia is contraindicated during pregnancy and should never be used by those who are pregnant or planning to become pregnant.

It’s a Category X drug, meaning it can cause birth defects like cleft lip or cleft palate, especially if taken during the first trimester. Because of this, Qsymia is strictly contraindicated during pregnancy.

Women of childbearing potential must have a negative pregnancy test before starting Qsymia and monthly thereafter. You must also use effective birth control the entire time you’re on Qsymia. If you become pregnant while taking Qsymia, stop the medication immediately and call your doctor.

Due to the risk of birth defects, Qsymia is only available through a special safety program called the REMS (Risk Evaluation and Mitigation Strategy) Program. This program ensures that prescribers and patients understand the risks and follow the necessary precautions to prevent pregnancy during treatment.

Eye problems

Qsymia can cause changes in your vision in rare cases. These usually go away when you stop taking the medicine. Sometimes, vision problems are a sign of a serious issue, like increased pressure inside the eye. This can happen within the first month of starting Qsymia.

Signs include blurry vision, a sudden decrease in vision with or without eye pain/redness, or blockage of fluid causing increased eye pressure. It can lead to permanent vision loss if untreated.

If you notice any change in your vision or have eye pain, get emergency medical help right away. Fast treatment can help protect your vision. If this happens, you’ll likely need to stop taking Qsymia.

Metabolic issues

Qsymia can cause metabolic problems, including low potassium levels and increased creatinine (a sign of kidney stress) and metabolic acidosis, where there’s too much acid in the blood.

Metabolic acidosis often has no symptoms at first, but if left untreated can lead to serious health issues like brittle bones (osteoporosis), kidney stones, and slowed growth in children. It’s important to catch and manage this condition early through regular blood tests.

Symptoms may include tiredness or weakness, loss of appetite, irregular or fast heartbeat, trouble thinking clearly or confusion, rapid or deep breathing.

If you experience any of these symptoms, call your doctor right away. Regular blood tests can help monitor acid levels, potassium, and kidney function to keep you safe while on Qsymia.

Kidney stones

Qsymia may increase the risk of developing kidney stones, especially since one of its ingredients, topiramate, can affect how the body handles minerals and acid levels.

To lower your risk, drink plenty of fluid, especially water, throughout the day to help flush your kidneys. Staying hydrated is one of the best ways to prevent stones from forming.

Watch for signs such as severe back or side pain, pain while urinating, or blood in your urine. If you notice any of these symptoms, call your doctor right away. Early treatment can help prevent more serious complications.

Cognitive impairment

Although not common, Qsymia can sometimes make it harder to think, focus, remember things, or find the right words when speaking.

These side effects are more likely if you’re taking a high dose, if your dose is increased too quickly, or if you mix Qsymia with alcohol or calming medicines like those for anxiety.

Like with dizziness, you should avoid driving or doing anything that requires full attention until you know how Qsymia affects you. It’s also best to limit or avoid alcohol while taking it.

If you notice any problems with thinking or memory, tell your doctor. They may lower your dose or suggest a different medication.

Severe skin reactions

Although rare, Qsymia can cause serious skin reactions, including dangerous conditions like Stevens-Johnson syndrome. These may appear as severe rashes, blisters, or peeling skin and can be life-threatening if not treated quickly.

Stop Qsymia and seek emergency medical help if you get a rash, blisters, or peeling skin (toxic epidermal necrolysis), especially if with fever or flu-like symptoms. Early treatment is critical to prevent complications.

Seizures (upon abrupt discontinuation)

Never stop taking Qsymia suddenly. Stopping the medication too quickly can cause seizures even if you’ve never had one before.

If you need to stop Qsymia, talk to your doctor first. They will create a tapering plan to safely reduce your dose and minimize the risk of seizures or other withdrawal symptoms.

Who should avoid Qsymia?

Qsymia should not be taken by people under 12 years old or who have any of the following:

• Heart disease
• Glaucoma
• Hyperthyroidism (overactive thyroid)
• Pregnant or planning to become pregnant
• Breastfeeding
• History of drug abuse
• Certain cardiovascular diseases (unstable angina, uncontrolled hypertension)
• MAOIs (monoamine oxidase inhibitors)* History of severe depression or suicidal ideation (due to bupropion component)
• Certain kidney or liver conditions
• Allergic to aspirin, phentermine, topiramate, or any inactive ingredients
• Dialysis
• History of substance misuse or dependency

Qsymia is not recommended for breastfeeding because one of its ingredients, topiramate, may cause diarrhea and sleepiness in breastfed babies.

Qsymia may worsen some medical conditions:

• Kidney or liver problems
• Epilepsy (seizures)
• Metabolic acidosis (too much acid in the blood)
• Depression or mood disorders
• Insomnia
• Glaucoma (eye condition)

Qsymia does not have an FDA black box warning, but tell your doctor about all the medicines, vitamins, and supplements you take. This will help them decide if Qsymia is right for you.

One of the ingredients in Qsymia, phentermine, is a controlled substance with a small risk of dependence or abuse. It’s related to sympathomimetic drugs like amphetamines and can speed up your nervous system, which may give you an “energy boost” or adrenaline-like feeling. This makes it a target for misuse, but when used correctly under a doctor’s care, dependence is rare.

If someone becomes dependent on phentermine, they may feel very tired or depressed if they stop taking it suddenly.

Topiramate is not addictive, but stopping it too quickly can cause seizures. If you want to stop Qsymia, your doctor can slowly taper your dose to minimize withdrawal symptoms or seizures.

Using Qsymia long-term may raise the risk of certain side effects. Topiramate has the potential to cause memory problems, trouble concentrating, and other thinking issues over time. Long-term use of Qsymia may also increase the risk of kidney stones, metabolic acidosis, and increased heart rate.

While on Qsymia, regular check-ups are very important to stay safe and healthy. Your healthcare professional may order blood tests to check your kidney function and acid levels in your blood. They’ll also monitor your heart rate and watch for signs of mood changes, depression, or anxiety. This ongoing monitoring will catch any serious side effects early and make sure the medication is working for you.

Taking too much Qsymia can be very dangerous and may be fatal, so use it exactly as your doctor tells you. Never take more than 15 mg/92 mg of phentermine/topiramate per day.

Signs of Qsymia overdose may include:

• Aggressive behavior
• Seeing or hearing things that aren’t real (hallucinations)
• Feeling very restless, then extremely tired
• Panic or confusion
• Mood or personality changes
• Depression or symptoms like schizophrenia
• Shaking (tremors)
• Fast breathing
• Blurry or double vision
• Dizziness
• Very low or high blood pressure
• Nausea, vomiting, or diarrhea
• Stomach cramps
• Seizures
• Passing out or a coma

If you think someone has taken too much Qsymia, call 911 or Poison Control at 1-800-222-1222 right away. Emergency treatment may include making the person vomit or having their stomach pumped at the hospital.

How to avoid Qsymia side effects

• Don’t get pregnant while on Qsymia. This medication can cause serious birth defects like cleft palate. If you can get pregnant, use birth control pills and take a pregnancy test every month. If you become pregnant, call your doctor right away.
• Don’t stop Qsymia suddenly. Stopping the medication all at once can cause seizures even if you’ve never had one before. If you need to stop or are having strong side effects, talk to your doctor; they can help you stop safely. Also, set reminders so you don’t miss a dose or run out.
• Drink plenty of water. Staying hydrated helps reduce side effects like dry mouth, skin tingling, constipation, and supports your kidneys. Avoid too much caffeine as it can make dehydration worse.
• Take it on time. If Qsymia keeps you awake, take it in the morning. If it makes you feel tired, talk to your doctor; they may suggest taking it at night instead.
• Go for regular checkups. Blood tests can catch serious problems early, like low potassium, kidney stones, or too much acid in the blood. Don’t wait for your next appointment, let your doctor know right away if something doesn’t feel right.
• Follow your doctor’s instructions exactly. Qsymia is usually taken once a day. You’ll start with a low dose and slowly increase it. Use a calendar or set an alarm to help you take the correct dose at the same time each day. Taking it the wrong way can lead to more side effects.

How to manage Qsymia side effects

If you have serious side effects like vision problems, kidney issues, or thoughts of self-harm, your doctor may suggest slowly stopping Qsymia. Other side effects, like constipation, trouble sleeping, or feeling down, might be managed by changing your dose or using other medicines.

Lifestyle adjustments

• Drink plenty of water throughout the day to help with dry mouth and kidney function.
• Add more fiber to your diet by eating fruits, vegetables, whole grains, and legumes to ease constipation.
• Stay physically active as regular movement can help with digestion, mood, and energy levels.
• Limit caffeine and alcohol, which can worsen side effects like dry mouth, insomnia, or dizziness.
• Stick to a regular sleep routine to manage insomnia—try going to bed and waking up at the same time each day.
• Eat small, balanced meals to help with appetite control and reduce stomach discomfort.
• Track your symptoms in a journal or app to notice patterns and share them with your doctor for better care.

Medical monitoring

• Regular checkups: Your doctor will check your heart rate and watch for mood changes like anxiety or depression while you’re on Qsymia.
• Blood tests: These help detect metabolic changes such as low potassium, high acid levels (metabolic acidosis), or early signs of kidney problems.
• Staying on top of these tests and appointments helps catch any issues early and keeps your treatment safe and effective.

Always talk to your doctor about any side effects so they can help you find the best solution for your needs.

When to stop the medication and seek medical attention

Stop Qsymia and seek medical attention right away if you experience any of the following:

• Chest pain – This could be a sign of a heart problem.
• Vision changes – Sudden eye pain, blurred vision, or any major changes in sight.
• Suicidal thoughts or behavior – If you or someone else notices mood changes, depression, or thoughts of self-harm.

These symptoms may be signs of serious side effects and need medical attention to prevent complications.

Qsymia vs. other weight loss drugs

Here is a comparison of Qsymia side effects vs. other popular weight loss drugs:

Drug interactions

If you take any of the following medicines, talk to your doctor before starting Qsymia, as it may increase the risk of side effects:

• Central nervous system (CNS) depressants: Qsymia can make the effects of certain drugs stronger, like alcohol, sleeping pills, barbiturates, and benzodiazepines. This may lead to side effects like dizziness, confusion, or trouble thinking clearly.
• Monoamine oxidase inhibitors (MAOIs): Taking Qsymia with MAOIs (a type of antidepressant) can cause high blood pressure. This combination is not safe and should never be used together.
• Hormonal contraceptives: Hormonal birth control may cause irregular spotting or bleeding when taken with Qsymia, but it will still work to prevent pregnancy.
• Diuretics: Diuretics (water pills) can lower potassium levels, and since Qsymia may also lower potassium, taking them together could make this worse.
• Other weight loss medications: It’s best not to use Qsymia with other weight loss drugs unless your doctor says it’s safe.
• Antiepileptic drugs: Taking phenytoin or carbamazepine with Qsymia may make topiramate (one of Qsymia’s active ingredients) less effective. Taking valproic acid with Qsymia may increase the risk of hypothermia and high ammonia levels in the blood.
• Carbonic anhydrase inhibitors: Qsymia with acetazolamide (Diamox) may increase the risk of kidney stones and metabolic acidosis (blood too acidic).
• Pioglitazone: Qsymia may make this type 2 diabetes medication less effective and raise blood sugar levels.
• Amitriptyline: Qsymia may increase the levels of amitriptyline in your body, so your doctor may lower the dose of this antidepressant.
• Alcohol: Avoid drinking alcohol while taking Qsymia. Alcohol can interact with the medication and increase the risk of drowsiness, dizziness, confusion, and poor coordination. The same applies if you take other calming drugs like barbiturates, benzodiazepines, or sleeping pills with Qsymia.

Tell your doctor about all the medications, supplements, and herbal products you’re taking. This helps avoid interactions and ensures Qsymia is safe for you to take.

FAQs

Does Qsymia cause weight regain after stopping?

Yes, stopping Qsymia can lead to weight regain if healthy habits are not continued. To keep the weight off, you need to continue a balanced diet and regular exercise even after stopping the medication.

Can Qsymia affect birth control effectiveness?

Qsymia doesn’t usually affect birth control. However, it may cause irregular spotting or bleeding in some people using hormonal birth control.

How long do Qsymia side effects last?

Most common side effects of Qsymia, like dry mouth or dizziness, usually improve as your body gets used to the medication. However, some side effects may last longer or continue if the medication is not adjusted. Talk to your doctor if they don’t go away.

Is Qsymia safe for long-term use?

Qsymia can be safe for long-term use if taken under a doctor’s care with regular check-ups. However, it may cause side effects over time, so your healthcare provider will monitor your health to make sure it’s safe for you.

How do I manage common Qsymia side effects like dry mouth, constipation, or insomnia?

For dry mouth, drink plenty of water and chew sugar-free gum. For constipation, eat more fiber and stay active; for trouble sleeping, avoid caffeine late in the day and try to keep a regular bedtime routine.

What are the long-term side effects or risks of Qsymia?

Long-term use of Qsymia may cause thinking or memory problems, kidney stones, and metabolic acidosis (a condition that makes your blood too acidic). It may also lower bone strength over time, so regular check-ups are important.

Who should NOT take Qsymia?

Pregnant women, people with certain heart problems, angle closure glaucoma, or overactive thyroid (hyperthyroidism) should not take Qsymia. It’s also not safe for those taking MAOIs or with a history of severe depression or suicidal thoughts.

Are there specific foods or drinks (like alcohol) I should avoid with Qsymia?

Yes, avoid alcohol while taking Qsymia as it can increase side effects like dizziness and confusion. There are no specific foods to avoid, but eating a healthy, reduced-calorie diet will help Qsymia work better.

Does Qsymia affect my heart rate or blood pressure?

Yes, Qsymia can increase your heart rate and, in some cases, blood pressure. Your doctor will check these regularly to make sure the medication is safe for you.

Does Qsymia affect my eyes or vision?

Yes, Qsymia can cause vision problems like blurred vision or, in rare cases, glaucoma. If you notice sudden eye pain or changes in your vision, tell your doctor right away.

Conclusion

Qsymia can be an effective weight management tool and improve health, but like all medications, it’s important to fully understand its potential side effects, both common (dry mouth or constipation) and serious (birth defects or mood changes), including those that may appear over the long term.

While common side effects are manageable and often go away as your body adjusts, serious or long-term risks like cognitive issues, kidney stones, or metabolic problems need to be monitored.

Never stop Qsymia suddenly, as this can cause seizures even in people without a history of epilepsy.

Staying hydrated, eating more fiber, and taking Qsymia at the right time can help reduce discomfort.

Qsymia isn’t for everyone, especially those who are pregnant, have certain medical conditions, or take interacting medications.

Being informed is the best tool to stay safe and get the most out of your treatment.

Talk to your healthcare provider openly. They are your best resource to help you weigh the benefits against the risks, manage any side effects, and decide if Qsymia is right and safe for you.