The efficacy of topiramate in the treatment of idiopathic intracranial hypertension (IIH) was compared to acetazolamide in an open-label study of 40 patients (age range 16-50, median 32 years; male/female ratio 5/35) at Ege University Medical School, Izmir, Turkey. Patients were assigned alternately to topiramate (100-150 mg daily) and acetazolamide (1000-1500 mg daily). CSF pressures (mmH20) ranged from 225-850, median 342 and 300, and were similar in the 2 groups at the beginning of the study. Visual fields compared at the end of the third, sixth, and twelfth month of the trial were significantly improved in both groups. Relief of headache occurred after a mean of 3.75 and 3.3 months treatment. Papilledema began to regress after the second month. Side effects of topiramate included distal paresthesias and concentration difficulties; acetazolamide caused fatigue and distal paresthesias. A prominent weight loss (mean 9.75 kg) in the topiramate group was significantly greater than in acetazolamide treated patients (p<0.001). Both drugs were equally effective in treatment of IIH. A placebo-controlled, double-blind trial of topiramate in IIH is recommended. 
COMMENT. Acetazolamide is the first-line drug in treatment of IIH. It acts by inhibiting carbonic anhydrase and reducing CSF production. Topiramate also inhibits carbonic anhydrase, and the mechanism of action in IIH may be similar to that of acetazolamide. The above patient cohort included some adolescents, but the majority were adults. Children with IIH differ from adults in a slight preponderance of male vs female and a much smaller incidence of obesity. Of 10 prepubertal pediatric patients studied at Children's Hospital Los Angeles, only one was obese, and the most common presenting signs were stiff neck, diplopia and strabismus. Papilledema and sixth nerve palsy resolved rapidly with acetazolamide. . A 14-year-old male adolescent with IIH and almost daily headache responded within 2 to 4 weeks following topiramate therapy. . The results of the Turkish study are of interest, and a trial of topiramate in children with IIH is warranted.