Acetazolamide (Diamox) (AZM) was tried as an adjunct to carbamazepine (CBZ) in 48 refractory partial seizure patients, the majority being adults and only 5 under 12 years of age. The seizures were complex partial in 80%, and idiopathic in 67%. A response measured by a 50% reduction in seizure frequency was obtained in 44% of patients, and side effects - lethargy, paresthesias, anorexia - were generally mild or transient. The duration of response ranged from 3 to 30 months and tolerance was not a major problem. Initial effective doses ranged from 3.8 to 16.5 mg/kg/day (mean, 8.2), and the maximum effective dose used was 22 mg/kg/day. The study was retrospective and uncontrolled, but the authors considered their results impressive and recommend AZM in preference to clonazepam as adjunctive therapy for partial seizures. [1]

COMMENT. Having been an advocate of acetazolamide for the treatment of refractory childhood seizures for several years (Millichap, JG et al. J Pharmacol & Exptl Therap 1955:115:251; Neurology 1956;6:552; Lancet July 18, 1987;2:163), I am happy to see that Dr. Penry and his associates now support its use in adults with partial seizures. AZM had previously been proposed as an alternative agent in the management of petit mal (absence) seizures in children, in menstruation-related seizures, and as an adjunct treatment in other refractory generalized and partial seizures of childhood. Despite the tendency for development of tolerance, which is also shared by the benzodiazepine agents, a review of published work in 1967 showed that AZM was equal in efficacy to ethosuximide and had a lower incidence of side effects [2]. At least as an adjunct therapy, the drug deserves wider recognition and confirmation of efficacy by controlled studies.