Yoshimura R, Shinkai K, Kakihara S, Goto M, Yamada Y, Kaji K, Ueda N, Nakamura J
Pharmacopsychiatry. 2005 Mar;38(2):98-100. doi: 10.1055/s-2005-837811.
In the present study, we investigated the effects of levomepromazine on plasma risperidone concentrations in a steady state. Twenty patients taking risperidone at a stable dose for more than 2 weeks who were considered to require levomepromazine coadministration were selected. The scores of excitement in BPRS significantly decreased 2 weeks after the coadministration of levomepromazine. Plasma risperidone concentrations and the ratio of risperidone and 9-hydroxyrisperidone (risperidone/9-hydroxyrisperidone) did not change between before and 2 weeks after the coadministration of levomepromazine. The extrapyramidal symptoms were not worsened by the coadministration of levomepromazine. These results suggest that a low dosage of levomepromazine, use as a sedative adjuvant to risperidone treatment, have no statistically significant effect on the trough plasma concentrations of risperidone.
