Carbamazepine in difficult to control epileptic out-patients.

Twenty-three difficult to control patients with 1 or more seizures per week despite diphenylhydantoin (DPH), phenobarbital and/or primidone in near and toxic doses and blood levels were entered in the study. 3 had grand mal. 8 psychomotor seizures and 12 had both. During a 6 1/2 month study period the patient received active drug and placebo for 3 months each; randomized, double-blind. The dose was to be increased within 4 weeks up to 6 capsules per day equal to 1,200 mg of carbamazepine (C), while the doses or previously taken (basis) anticonvulsants were to remain unchanged. Hematopoetic system and heptic functions were monitored. Complete seizure control attributable to C was not achieved in any, but up to 50% improvement occurred in 12 patients. Questionable improvement was thought to take place in 3 patients, no change occurred in 7, and psychomotor seizures became more frequent in 1 patient. A clear-cut psychotropic effect was not observed. Adverse effects attributable to C were a decline of WBC below 4,000 with relative neutropenia in 3 patients followed by at return to the previous after discontinuation of C. Nystagmus and unsteadiness were seen in about half of the patients, and some headache and drowsiness occurred in one quarter. The highest C blood level was 11.8 mug/ml, the lowest 3.8 mug/ml (average 5.6 mug/ml) during 1,200 mg intake. It seemed, generally, that intoxication occurred with lower blood levels of carbamazepine in those patients whose basis anticonvulsant blood levels were highest.