Use of acetazolamide as an adjunct to carbamazepine in refractory partial seizures

Acetazolamide (Diamox) (AZM) was evaluated as an adjunct to carbamazepine (CBZ) monotherapy in 48 refractory partial seizure patients at a tertiary care referral center. Patient ages ranged from 6 to 64 years (average 28 years). Seizure frequencies for the pre-AZM baseline period (CBZ monotherapy) were compared with the seizure frequencies at different daily doses of AZM. Patients with a 50% decrease in seizure frequency were considered responders. Twenty-one patients were responders (44%) and three became completely seizure-free. Effective doses ranged from 3.8 to 22.0 mg/kg/day. Effective plasma concentrations ranged from 1 to 22 micrograms/ml in selected patients. Durations of response time to AZM ranged from 3 to 30 months (average 12.9 months). Three patients lost response, one temporarily. Side effects were seen in 10 patients, requiring discontinuation in three.