Side Effects of Topamax: What to Know

Topamax is a brand-name prescription drug. It’s a type of drug called an anticonvulsant, and it contains the active drug topiramate.

Topamax comes as oral tablets and sprinkle capsules. (Sprinkle capsules can be swallowed whole or opened and their contents sprinkled onto food.)

Topamax is approved by the Food and Drug Administration (FDA) to:

• prevent migraine episodes in adults and children ages 12 years and older
• treat epilepsy with certain seizure types in adults and children ages 2 years and older

Doctors typically prescribe Topamax for long-term use.

Similar to other drugs, Topamax may cause side effects. Read below for information about possible side effects, including common, mild, and serious ones.

For a general overview of Topamax, including details about its uses, see this article. If you’d like to take Topamax, search here to find a healthcare professional who might prescribe it.

Some side effects of Topamax may be more common than others. These side effects may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about any side effects with Topamax.

Some of the more common side effects of Topamax that occurred during clinical studies are listed below. These side effects can vary depending on the condition Topamax is being used to treat.

In people taking Topamax for migraine, more common side effects include:

• changes in the way things taste
• loss of appetite
• sensations of numbness, burning, or tingling in the hands or feet
• weight loss
• memory loss*

In people taking Topamax for epilepsy, more common side effects include:

• fatigue
• loss of appetite
• problems with speech, such as having trouble thinking of the right words
• sensations of numbness, burning, or tingling in the hands or feet
• weight loss

* For more information about this side effect, see “Topamax: Side effects explained” below.

Topamax can cause mild side effects, which are listed below. However, this list doesn’t include all possible mild side effects. To learn more about the side effects of Topamax, view the drug’s prescribing information.

Mild side effects of Topamax include:

• abdominal pain
• changes in the way things taste
• constipation
• diarrhea
• dizziness
• dry mouth
• fatigue
• fever
• loss of appetite
• problems with speech, such as trouble thinking of the right words
• sensations of numbness, burning, or tingling in the hands or feet
• sexual side effects, such as decreased sex drive or premature ejaculation
• sleepiness
• slowed physical or mental reactions
• upper respiratory infection, such as the common cold
• weight loss
• hair loss*
• nausea*

The side effects listed above may last only a few days to weeks. However, some side effects may last longer or become severe or bothersome. Tell your doctor or pharmacist if you have concerns about side effects with Topamax.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Topamax and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Topamax: Side effects explained” below.

It’s possible to have serious side effects with Topamax. Serious side effects are listed below, but this list may not include all possibilities. To learn more about the side effects of Topamax, view the drug’s prescribing information.

Call your doctor right away if you have serious side effects with Topamax. However, if you think you’re having a medical emergency or life threatening side effects, call 911 or your local emergency number.

Serious side effects of Topamax and their possible symptoms include:

• Kidney stones. Symptoms can include:
  • pain with urination
  • blood in urine
  • back pain
  • lower abdominal pain
  • nausea and vomiting
• High ammonia level in the blood. Symptoms can include:
  • fatigue
  • loss of appetite
  • nausea
  • weakness
• Metabolic acidosis (very high level of acid in the blood). Symptoms can include:
  • heart palpitations
  • confusion
  • headache
  • shortness of breath or rapid breathing
• Reduced sweating, which can cause hyperthermia (very high body temperature). Symptoms can include:
  • flushing
  • headache
  • lightheadedness
  • muscle cramps
• Severe skin reaction, including Stevens-Johnson syndrome. Symptoms can include:
  • fever
  • peeling skin
  • rash
  • blisters
• Eye side effects.*
• Mood changes.*
• Memory loss.*
• Allergic reaction.*†

* For more information about this side effect, see “Topamax: Side effects explained” below.
† An allergic reaction is possible after taking Topamax. However, this side effect was not reported in clinical studies.

Topamax is used to:

• prevent migraine in children ages 12 years and older
• treat epilepsy with certain seizure types in children ages 2 years and older

Most side effects of Topamax are expected to be the same in children as they are in adults. However, the following side effects may be more likely in children:

• reduced sweating, which can cause hyperthermia (very high body temperature)
• reduced height
• low bone mineral density, which can be a sign of weakened bones
• pink eye

On the other hand, slowed physical or mental reactions and problems with speech may be less likely in children.

If you have questions about your child’s risk of side effects with Topamax, talk with their doctor or pharmacist.

Here are some common questions about the drug’s side effects and their answers. Talk with your doctor if you have other questions about this drug.

Most side effects of Topamax are temporary and go away soon after you start or stop taking the drug.

However, in rare cases, severe side effects of Topamax could lead to long-term problems. And some could cause permanent damage. For example, Topamax may cause glaucoma as a side effect.* If it isn’t treated, glaucoma can lead to long-term vision loss.

If you have questions about possible permanent or long-term side effects with Topamax, talk with your doctor or pharmacist.

* For more information about this side effect, see “Topamax: Side effects explained” below.

Withdrawal symptoms weren’t reported as side effects in clinical studies of Topamax. (Withdrawal symptoms may happen after you suddenly stop taking certain drugs that your body is dependent on. With dependence, your body needs the drug in order to function like usual.)

However, stopping Topamax could cause you to have symptoms of the condition you’re treating. For example, if you’re taking Topamax to treat epilepsy, stopping the drug could increase your risk of having a seizure.

For this reason, it’s important that you do not stop taking Topamax unless your doctor says it’s safe. When it’s time to stop taking Topamax, your doctor will gradually lower your dosage over time. This helps lower your risk of having symptoms return.

If you have bothersome side effects with Topamax, talk with your doctor or pharmacist. They can advise on ways to help ease your symptoms.

For example, loss of appetite and weight loss are common side effects of Topamax. If you have these side effects, your doctor can suggest ways to help you maintain a healthy appetite and body weight while you’re taking the drug.

For details on how to manage certain other side effects of Topamax, see the “Topamax: Side effects explained” section below.

It’s possible. In clinical studies of Topamax, certain side effects occurred more often with higher doses of the drug than with lower doses.

For example, the following side effects were more likely with higher doses of Topamax compared with lower doses:

• memory loss*
• sensations of numbness, burning, or tingling in your hands or feet
• sleepiness
• fatigue
• dizziness

Talk with your doctor if you have questions about your risk of side effects based on your Topamax dosage.

* For more information about this side effect, see “Topamax: Side effects explained” below.

It’s not likely. With euphoria, you feel extreme happiness or excitement. This symptom wasn’t reported as a side effect in clinical studies of Topamax.

However, Topamax may cause mood changes other than euphoria. For more information, see “Mood changes” in the “Topamax: Side effects explained” section below.

Heart palpitations and weight gain weren’t reported as side effects in clinical studies of Topamax.

In fact, Topamax is more likely to cause weight loss than weight gain. Weight loss was a common side effect in studies of the drug.

Heart palpitations can be a symptom of metabolic acidosis, which is a possible side effect of Topamax. (Metabolic acidosis refers to a very high level of acid in the blood.) However, heart palpitations alone weren’t reported as a side effect in the drug’s studies.

If you have questions about heart palpitations or weight gain with Topamax, talk with your doctor.

It’s not likely. Side effects after missing a dose of the drug weren’t reported in clinical studies of Topamax.

However, keep in mind that missing a dose of Topamax could cause you to have symptoms of the condition Topamax is treating. For example, if you’re taking Topamax to treat epilepsy, missing a dose could increase your risk of having a seizure.

You can try these tips to help avoid missing a dose of Topamax. You may also find it helpful to use a timer, set an alarm, or download a reminder app on your phone.

Here’s detailed information about some of Topamax’s side effects.

Topamax may cause hair loss. However, this side effect was rare in clinical studies of the drug.

Hair loss was only reported by people who took Topamax to treat epilepsy. People who took Topamax for migraine prevention didn’t report this side effect.

If you have hair loss while you’re taking Topamax, talk with your doctor. In many cases, hair loss with Topamax is reversible. Hair is expected to grow back after Topamax treatment is stopped.

If you’re concerned about Topamax and hair loss, talk with your doctor or pharmacist.

Ocular (eye) side effects are possible with Topamax.

Certain eye side effects were common in clinical studies of Topamax. Examples include blurred vision and double vision.

In rare cases, Topamax may cause severe eye side effects, such as:

• decreased vision
• nearsightedness
• glaucoma, which typically causes eye pain and sudden vision loss

The risk of glaucoma with Topamax is typically highest in the first month of treatment with the drug.

If you have bothersome eye side effects while taking Topamax, call your doctor. They may order tests to make sure you aren’t having severe eye problems.

However, you should tell your doctor right away if you have symptoms of glaucoma while taking Topamax. They’ll likely have you stop taking the drug as soon as possible. Your doctor may also suggest treatment other than Topamax for your condition.

Topamax may cause certain mood changes.

Nervousness was a common side effect in clinical studies of Topamax. However, other mood changes were less common. Examples of these less common mood changes include:

• aggression
• agitation
• anxiety
• depression
• uncontrollable laughing or crying
• suicidal thoughts and behaviors

If you have any unusual mood changes while taking Topamax, tell your doctor right away. They may recommend a drug other than Topamax for your condition.

However, if you have suicidal thoughts while taking Topamax, call 911 or your local emergency number right away.

Suicide prevention

If you know someone at immediate risk of self-harm, suicide, or hurting another person:

• Ask the tough question: “Are you considering suicide?”
• Listen to the person without judgment.
• Call 911 or the local emergency number, or text TALK to 741741 to communicate with a trained crisis counselor.
• Stay with the person until professional help arrives.
• Try to remove any weapons, medications, or other potentially harmful objects.

If you or someone you know is having thoughts of suicide, a prevention hotline can help. The National Suicide Prevention Lifeline is available 24 hours per day at 800-273-8255. During a crisis, people who are hard of hearing can use their preferred relay service or dial 711 then 800-273-8255.

Click here for more links and local resources.

Memory loss is possible with Topamax. This was a more common side effect in clinical studies of the drug.

Your risk of memory loss may be greater if you take higher doses of Topamax.

If you have memory loss with Topamax, tell your doctor. They may prescribe a lower dosage of Topamax for you. Or your doctor may suggest a different medication for your condition.

Taking Topamax may cause nausea. This was one of the most common side effects in clinical studies of the drug.

Along with nausea, you may have other digestive problems with Topamax. Examples include:

• abdominal pain
• constipation
• diarrhea
• loss of appetite

If you have bothersome nausea while taking Topamax, talk with your doctor. They can suggest ways to reduce this side effect. In severe cases, your doctor may prescribe medications to help ease your discomfort.

You can take doses of Topamax with or without food. However, taking the drug with food could help lessen nausea or other digestive problems you may have.

Be sure to talk with your doctor about your health history before taking Topamax. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health.

The conditions and factors to consider include those described below.

Kidney problems. Before taking Topamax, tell your doctor about any kidney problems you have. Having kidney issues could increase your risk of certain side effects with Topamax. Examples include kidney stones and metabolic acidosis (very high level of acid in the blood). If you have kidney problems, your doctor may monitor certain blood tests more closely than usual while you’re taking Topamax. They may also give you a lower dosage of Topamax than what’s typically prescribed.

Bone problems. Topamax may cause metabolic acidosis (very high level of acid in the blood). This side effect could increase your risk of bone problems such as osteoporosis. If you already have bone problems, talk with your doctor before taking Topamax. They can advise if it’s safe for you to take the drug.

Glaucoma. Before taking Topamax, tell your doctor if you have glaucoma. Topamax may cause a glaucoma attack (sudden blurred vision or eye pain) in people with this condition. Your doctor can recommend whether it’s safe to take Topamax.

Liver problems. Before starting Topamax treatment, tell your doctor about any liver problems you have. Liver problems can increase your risk of having a high ammonia level in the blood as a side effect. Your doctor can advise if Topamax is a safe treatment option for you.

Lung or breathing problems. Before taking Topamax, tell your doctor if you have any lung or breathing problems. You may have a higher risk of metabolic acidosis (very high level of acid in the blood) as a side effect of the drug. Your doctor can recommend if Topamax is right for you.

Suicidal thoughts or depression. In rare cases, Topamax may cause depression or suicidal thoughts and behaviors. Before taking Topamax, tell your doctor if you already have these conditions. Your doctor can recommend if it’s safe for you to take Topamax.

Allergic reaction. If you’ve had an allergic reaction to Topamax or any of its ingredients, your doctor will likely not prescribe Topamax. Ask your doctor what other medications may be better options for you.

Ketogenic diet. Before starting treatment with Topamax, tell your doctor if you follow a ketogenic diet. This type of diet could raise your risk of kidney stones and metabolic acidosis (very high level of acid in the blood). Your doctor can recommend if it’s safe for you to take Topamax while you’re following a ketogenic diet.

You should not consume alcohol during Topamax treatment. Alcohol could worsen certain side effects of the drug, such as dizziness and sleepiness.

If you have questions about drinking alcohol while taking Topamax, talk with your doctor.

Below is information about pregnancy and breastfeeding while taking Topamax.

It may not be safe to take Topamax while you’re pregnant.

Topamax may cause side effects in children born to people who took the drug during pregnancy. Examples of these side effects include:

• smaller body size than usual for their age
• cleft lip
• cleft palate

If you’re pregnant or planning to become pregnant, talk with your doctor before taking Topamax. They’ll likely recommend a different treatment option for you.

If you take Topamax while pregnant, consider enrolling in a pregnancy registry for the drug. Pregnancy registries help doctors and researchers understand more about the risks of taking certain drugs during pregnancy. To learn more about the North American Antiepileptic Drug Pregnancy Registry, talk with your doctor. You can also visit the registry’s site or call 888-233-2334.

It may not be safe to take Topamax while you’re breastfeeding. The drug could pass into breast milk. And this can cause side effects in a breastfed child, such as sleepiness or diarrhea.

If you’re breastfeeding or planning to do so while taking Topamax, talk with your doctor. They can recommend if this is safe to do.

Talk with your doctor or pharmacist to find out more information about Topamax. If you have questions about the drug’s side effects, your pharmacist or healthcare professional can help answer them for you.

In addition to discussing Topamax with your doctor, consider reading the following articles to learn more.

• Overview of Topamax. To read an overview of Topamax, see this article.
• Drug comparison. To learn how Topamax compares with Banzel, read this article. For information about Topamax versus Emgality, view this article. And if you’d like to know about Topamax and Trokendi XR, check out this article.
• Details about Topamax’s uses. To learn more about the conditions Topamax is used for, see these articles about migraine and epilepsy.

Disclaimer: Healthgrades has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.