Topamax (topiramate) is classified as an anticonvulsant. Topamax effectively controls partial onset seizures in patients, both adults and children, and generalized tonic-clonic seizures. Topamax is also used to help prevent migraines. Doses range from 25 mg to a maximum dose of 1600 mg daily for adults. Pediatric doses begin at 1 to 3 mg per kg until a target dose range of 5 to 9 mg per kg is reached.
Generalized Side Effects
Reported Topamax side effects that affect the body as a whole are fatigue, weight loss and difficulty speaking. In children, decreased sweating and hyperthermia is reported. The National Institute of Health (NIH) reports metabolic acidosis is a relatively common side effect, which, if it occurs, happens early in treatment. Effects may be mild to moderate depending on any other health conditions a patient may have that would predispose the patient to serious complications.
Central Nervous System Side Effects
The NIH reports that the most common central nervous system side effects associated to Topamax use are categorized as somnolence (sleepiness) and fatigue, psychomotor and cognitive impairments. Dizziness, difficulty with speech, ataxia (impaired coordination during voluntary movement), slowed responses, memory impairment, difficulty concentrating and confusion are potential adverse reactions.
Irritability, nervousness, anxiety and depression may also occur while taking Topamax. Parasthesia (weakness, numbness and tingling) and tremor are possible, as well as nystagmus, which is involuntary movement of the eye. The NIH reports that patients should seek immediate medical care if they experience blurred vision, visual disturbances or periorbital pain (pain around the eye) while taking Topamax.
Gastrointestinal Side Effects
The most severe gastrointestinal (GI) side effect reported is anorexia. Patients who experience this may have significant weight loss and need to take in additional calories either through consuming more food or supplements. Other adverse GI effects associated with Topamax use are altered taste, dry mouth, indigestion, diarrhea and constipation.
Hematologic and Immune System Side Effects
The NIH reports that Topamax may affect red blood cell production, resulting in anemia. Topamax also may inhibit white blood cell production and function, increasing a patient's risk for infection.
Respiratory System Side Effects
Topamax may cause bronchitis, rhinitis and difficulty breathing in some patients. Patients should report shortness of breath to a health care provider.
Dermatologic Side Effects
Some patients have experienced rash, itching and acne while taking Topamax.
References
- National Institute of Health
- Wilson, B. A., Shannon, T. M., & Shields, K. M. (2010). Pearson Nurse's Drug Guide 2010. New York: Pearson.
