Interaction between carbamazepine and bromperidol.
OBJECTIVE
The interaction between carbamazepine and bromperidol was studied in 13 schizophrenic inpatients.


METHODS
Before carbamazepine addition, the subjects were taking bromperidol 12-24 mg.day-1 for 1-20 weeks. Carbamazepine 400 mg.day-1 was coadministered for 4 weeks, and blood samplings were performed before carbamazepine addition and at weekly intervals after the addition. Plasma concentrations of bromperidol and its reduced metabolite were measured by high-performance liquid chromatography.


RESULTS
Carbamazepine significantly decreased plasma concentrations of both bromperidol and reduced bromperidol for all weeks. On average, the plasma concentrations of bromperidol and reduced bromperidol at 4 weeks were 37% and 23% of the corresponding precarbamazepine values. Despite these decreases in plasma concentration, the Clinical Global Impression scores decreased slightly but significantly after carbamazepine addition.


CONCLUSIONS
The present study suggests that carbamazepine decreases plasma concentrations of bromperidol and its reduced metabolite by inducing the metabolism of these compounds. Nevertheless, adjunctive carbamazepine may be useful for schizophrenic patients treated with bromperidol.
Otani
K
K
Department of Neuropsychiatry, Hirosaki University Hospital, Japan.
Ishida
M
M
Yasui
N
N
Kondo
T
T
Mihara
K
K
Suzuki
A
A
Furukori
H
H
Kaneko
S
S
Inoue
Y
Y
D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000097:blood / Q000494:pharmacology*; D014150:Antipsychotic Agents / Q000097:blood / Q000493:pharmacokinetics*; D002220:Carbamazepine / Q000097:blood / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004347:Drug Interactions; D005260:Female; D006220:Haloperidol / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000097:blood / Q000188:drug therapy
D018712:Analgesics, Non-Narcotic; D014150:Antipsychotic Agents; D002220:Carbamazepine; D006220:Haloperidol; C006820:bromperidol