2018 年 10 巻 1 号 p. 68-72
We examined the effects of switching from carbamazepine to lacosamide on plasma concentrations of risperidone and its active metabolite 9-hydroxyrisperidone in two patients with partial epilepsy manifesting epileptic psychosis. Within 1 week of switch, increases of 52.5-347% in plasma levels of risperidone and 9-hydroxyrisperidone were observed, along with improvements in psychiatric symptoms as shown by Positive and Negative Syndrome Scale scores (PANSS). Neither of the patients showed extrapyramidal symptoms or seizures during 3 months after switching. The present results support the notion that carbamazepine (CBZ) administration induces hepatic microsomal enzyme systems that regulate inactivation of antipsychotic drugs. When CBZ and psychotropic agents are used in combination, a switch from CBZ to lacosamide may be effective in patients with treatment-resistance epileptic psychosis.
