Effects of escitalopram on plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, in Japanese patients.
BACKGROUND
The effects of escitalopram (10 mg/d) coadministration on plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, were studied in 13 Japanese psychiatric patients and compared with those of paroxetine (10 mg/d) coadministration.


METHODS
The patients had received 6-24 mg/d of aripiprazole for at least 2 weeks. Patients were randomly allocated to one of 2 treatment sequences: paroxetine-escitalopram (n=6) or escitalopram-paroxetine (n=7). Each sequence consisted of two 2-week phases. Plasma concentrations of aripiprazole and dehydroaripiprazole were measured using liquid chromatography with mass spectrometric detection.


RESULTS
Plasma concentrations of aripiprazole and the sum of aripiprazole and dehydroaripiprazole during paroxetine coadministration were 1.7-fold (95% confidence intervals [CI], 1.3-2.1, p<0.001) and 1.5-fold (95% CI 1.2-1.9, p<0.01) higher than those values before the coadministration. These values were not influenced by escitalopram coadministration (1.3-fold, 95% CI 1.1-1.5 and 1.3-fold, 95% CI 1.0-1.5). Plasma dehydroaripiprazole concentrations remained constant during the study.


CONCLUSIONS
The present study suggests that low doses of escitalopram can be safely coadministered with aripiprazole, at least from a pharmacokinetic point of view.
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
K
K
Nemoto
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
K
K
Mihara
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
A
A
Nakamura
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
G
G
Nagai
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
S
S
Kagawa
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
T
T
Suzuki
Department of Neuropsychiatry Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
T
T
Kondo
D000328:Adult; D000068180:Aripiprazole; D044466:Asian People; D015283:Citalopram / Q000097:blood* / Q000627:therapeutic use; D065731:Cytochrome P-450 CYP2C19 / Q000235:genetics; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D004569:Electroencephalography; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000097:blood* / Q000188:drug therapy / Q000235:genetics; D008875:Middle Aged; D017374:Paroxetine / Q000097:blood / Q000627:therapeutic use; D010879:Piperazines / Q000097:blood* / Q000627:therapeutic use; D015363:Quinolones / Q000097:blood* / Q000627:therapeutic use
D010879:Piperazines; D015363:Quinolones; D015283:Citalopram; C517414:dehydroaripiprazole; D017374:Paroxetine; D000068180:Aripiprazole; D065731:Cytochrome P-450 CYP2C19; D019389:Cytochrome P-450 CYP2D6