Little effects of low dosage of levomepromazine on plasma risperidone levels.
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.
Yoshimura
R
R
Shinkai
K
K
Kakihara
S
S
Goto
M
M
Yamada
Y
Y
Kaji
K
K
Ueda
N
N
Nakamura
J
J
D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000097:blood* / Q000378:metabolism; D010054:Brief Psychiatric Rating Scale; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008728:Methotrimeprazine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use*; D008875:Middle Aged; D011618:Psychotic Disorders / Q000188:drug therapy*; D018967:Risperidone / Q000097:blood* / Q000378:metabolism
D014150:Antipsychotic Agents; D008728:Methotrimeprazine; D018967:Risperidone