Further observations on carbamazepine plasma levels in epileptic patients

Abstract

Plasma levels of carbamazepine, phenytoin and phenobarbital were monitored weekly over a period of 9 weeks in 20 epileptic patients unresponsive to treatment. No attempts were made to modify phenytoin and/or phenobarbital plasma levels; emphasis was on achieving carbamazepine plasma levels of 4 to 10ug per milliliter. A remarkable drop in siezure frequency was attained within 2 to 3 weeks of monitoring, with carbamazepine plasma concentrations within the desired range. Children disposed of the drug faster than adults. No effects of phenytoin and phenobarbital on carbamazepine levels. Transient leukopenia was present in most of the pateints, while a significant reversible drop in red blood cells was observed in eight patients. The data reported confrim that with a careful monitoring of drug plasma levels, carbamazepine may exert a definite passive effect on seizure frequency in epileptic patients poorly responsive ot therapy.