INFLUENCE OF PHENOBARBITAL AND DIPHENYLHYDANTOIN ON PLASMA CARBAMAZEPINE LEVELS IN PATIENTS WITH EPILEPSY

Abstract

A total of 123 patients with epilepsy, trigeminal neuralgia or other pains were treated with carbamazepine, which was given alone in 30, with diphenylhydantoin in 48, with phenobarbital in 18 and in 27 cases all three drugs were given. Carbamazepine was determined by quantitative thin-layer chromatography with subsequent in situ measurement of fluorescence. The plasma level of carbamazepine was higher when the patients were treated with carbamazepine alone than when they were treated as well with diphenylhydantoin or phenobarbital or with both. The difference was highly significant. Various possible explanations for this difference are discussed.