Topiramate (Topamax) is a medicine that is usually used to control seizures or relieve chronic pain. This medicine is used to reduce the urge to binge in people who have binge eating disorder. Topiramate also might help a person lose weight.

This medicine lowers some people's appetites. It is not clear how topiramate helps with weight loss, but experts believe that it affects brain chemicals called neurotransmitters.

Common side effects of topiramate include:

• Fatigue.
• A prickling or tingling sensation in the hands and feet.
• Lack of coordination.
• Loss of appetite and weight loss.
• Inability to concentrate or speak clearly.

Topiramate has been linked in some people to a potentially life-threatening condition called metabolic acidosis, which happens when there is too much acid in the blood. Symptoms include fatigue, lack of appetite, and rapid breathing (hyperventilation). If left untreated, metabolic acidosis can lead to death.

In rare cases, topiramate may cause serious side effects, such as:

• Glaucoma, which can lead to blindness.
• An inability to sweat, which can lead to life-threatening fever or heatstroke.

The U.S. Food and Drug Administration (FDA) has issued a warning on seizure medicines and the risk of suicide and suicidal thoughts. The FDA does not recommend that people stop using these medicines. Instead, people who take seizure medicine should be watched closely for warning signs of suicide. People who take seizure medicine and who are worried about this side effect should talk to a doctor.

What to think about

• You should not use this medicine if you are breast-feeding.
• If you are taking this medicine, drink plenty of fluids.
• If you are taking this medicine, call your doctor if you have blurred vision or eye pain.