Topiramate, sold under the brand name Topamax among others, is a carbonic anhydrase inhibitor medication used to treat epilepsy and prevent migraines. It has also been used in alcohol dependence. For epilepsy this includes treatment for generalized or focal seizures. It is taken by mouth.Common side effects include tingling, feeling tired, loss of appetite, abdominal pain, weight loss, and decreased cognitive function such as trouble concentrating. Serious side effects may include suicide, increased ammonia levels resulting in encephalopathy, and kidney stones. Use in pregnancy may result in harm to the baby and use during breastfeeding is not recommended. How it works is unclear.Topiramate was approved for medical use in the United States in 1996. It is available as a generic medication. In 2020, it was the 57th most commonly prescribed medication in the United States, with more than 11 million prescriptions. Medical uses
Topiramate is used to treat epilepsy in children and adults, and it was originally used as an anticonvulsant. In children, it is indicated for the treatment of Lennox-Gastaut syndrome, a disorder that causes seizures and developmental delay. It is most frequently prescribed for the prevention of migraines as it decreases the frequency of attacks. Topiramate is used to treat medication overuse headache and is recommended by the European Federation of Neurological Societies as one of the few medications showing effectiveness for this indication. Pain
A 2018 review found topiramate of no use in chronic low back pain.
In children, overdose may also result in hallucinations. Topiramate has been deemed the primary substance that led to fatal overdoses in cases that were complicated by polydrug exposure. The most common signs of overdose are dilated pupils, somnolence, dizziness, psychomotor agitation, and abnormal, uncoordinated body movements.Symptoms of overdose may include but are not limited to:

A specific antidote is not available. Treatment is entirely supportive. Interactions
Topiramate has many drug-drug interactions. Some of the most common are listed below:

As topiramate inhibits carbonic anhydrase, use with other inhibitors of carbonic anhydrase (e.g. acetazolamide) increases the risk of kidney stones. Enzyme inducers (e.g. carbamazepine) can increase the elimination of topiramate, possibly necessitating dose escalations of topiramate. Topiramate may increase the plasma-levels of phenytoin. Topiramate itself is a weak inhibitor of CYP2C19 and induces CYP3A4; a decrease in plasma levels of estrogens and digoxin has been noted during topiramate therapy. This can reduce the effectiveness of oral contraceptives (birth control  pills); use of alternative birth control methods is recommended. Neither intrauterine devices (IUDs) nor Depo-Provera are affected by topiramate. Alcohol may cause increased sedation or drowsiness, and increase the risk of having a seizure. As topiramate may result in acidosis other treatments that also do so may worsen this effect. Oligohidrosis and hyperthermia were reported in post-marketing reports about topiramate; antimuscarinic drugs (like trospium) can aggravate these disorders. Pharmacology
The topiramate molecule is a sulfamate modified sugar, more specifically, fructose diacetonide, an unusual chemical structure for a pharmaceutical. Topiramate is quickly absorbed after oral use.