title: Serum levels of aripiprazole and dehydroaripiprazole, clinical response and side effects.
abstract: Aripiprazole, a novel antipsychotic drug, is metabolized by CYP3A4 and CYP2D6 forming mainly its active metabolite dehydroaripiprazole. In this study, aripiprazole and dehydroaripiprazole serum levels of psychiatric patients were measured and related to dose, comedication, and clinical effects including therapeutic and side effects. Patients were treated with mean doses of 20 +/- 8 mg/day of aripiprazole (median 15 mg, range 7.5-60 mg). Serum levels correlated significantly with the dose (r = 0.419; P < 0.01), with a mean value of aripiprazole of 214 +/- 140 ng/ml. Mean concentrations of the active metabolite dehydroaripiprazole amounted to 40% of the parent compound. Comedication with CYP3A4 and CYP2D6 inducers or inhibitors changed serum levels up to 51%. Improvement was best in patients with a serum level between 150 and 300 ng/ml. No or only mild side effects were detected in patients, with aripiprazole plasma concentrations between 110 and 249 ng/ml. A total of 32% of the patients who received no other antipsychotic drug besides aripiprazole reported side effects; tension being the most frequent one. Since serum levels of aripiprazole and dehydroaripiprazole were highly variable between individuals, and distinct ranges were associated with good therapeutic response and minimal side effects, it seems likely that therapeutic drug monitoring can be helpful to improve the antipsychotic drug therapy.
authors.affiliation: Department of Psychiatry, University of Mainz, Germany.
authors.forename: Katrin M
authors.initials: KM
authors.lastname: Kirschbaum
authors.forename: Matthias J
authors.initials: MJ
authors.lastname: Müller
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Malevani
authors.forename: Arian
authors.initials: A
authors.lastname: Mobascher
authors.forename: Carsten
authors.initials: C
authors.lastname: Burchardt
authors.forename: Markus
authors.initials: M
authors.lastname: Piel
authors.forename: Christoph
authors.initials: C
authors.lastname: Hiemke
mesh_terms: D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use*; D000068180:Aripiprazole; D019389:Cytochrome P-450 CYP2D6 / Q000378:metabolism; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use*; D015363:Quinolones / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use*; D012559:Schizophrenia / Q000097:blood* / Q000188:drug therapy* / Q000378:metabolism
chemical_list: D014150:Antipsychotic Agents; D010879:Piperazines; D015363:Quinolones; C517414:dehydroaripiprazole; D000068180:Aripiprazole; D019389:Cytochrome P-450 CYP2D6; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human