CARBAMAZEPINE-INDUCED CHANGES IN PLASMA-LEVELS OF NEUROLEPTICS

We compared the effect of carbamazepine and oxcarbazepine treatment on the plasma levels of clozapine and thioridazine in 12 patients. There was a 47 % decrease in the plasma levels of clozapine (p<0.005, Stude nts two-tailed t-test) during carbamazepine treatment, while the effec ts on the thioridazine levels were less marked (n.s.). Since carbamaze pine is also used in patients receiving concurrent clozapine therapy, it is important to take this marked interaction between these two drug s into account.