• Two patients suffered overdoses of anticonvulsant drugs. The first patient took methsuximide and the second, phenytoin. Because of profound CNS depression, both patients underwent hemoperfusion with a cellulose-activated charcoal hemoperfusion column. The primary metabolite of methsuximide, N-desmethylmethsuximide, primarily was responsible for the CNS depression in the first patient. The clearance of N-desmethylmethsuximide by the charcoal column was high, and clinical improvement became apparent during the hemoperfusion period. The clearance of phenytoin, on the other hand, was much lower than that of N-desmethylmethsuximide, and there was no apparent clinical improvement in that patient's condition.
(Arch Intern Med 140:1466-1468, 1980)