Quetiapine is an atypical antipsychotic, used clinically in the treatment of schizophrenia, acute mania in bipolar disorders, and
bipolar depression in adults. In this study, the effect of green tea extracts (GTE) on the pharmacokinetics of quetiapine (substrate
of CYP3A4) was investigated in rats. Male Wistar albino rats received GTE (175 mg/kg) or saline (control) by oral gavage for 7
days before a single intragastric administration of 25 mg/kg quetiapine. Plasma concentrations of quetiapine were measured up to
12 h after its administration by a validated ultraperformance liquid chromatography-tandem mass spectroscopy. Pretreatment with
GTE produced significant reductions in the maximum plasma concentration and area under the curve of quetiapine by 45% and
35%, respectively, compared to quetiapine alone. However, GTE did not produce significant change in elimination half-life and oral
clearance of quetiapine. This study concluded that GTE may decrease the bioavailability of quetiapine when coadministered.