Abstract
OBJECTIVES: This study aimed to assess the interaction between metoprolol and Ginkgo tablets during their co-administration to provide a reference for clinical prescribing. METHODS: The co-administration of metoprolol (20 mg/kg) and Ginkgo tablets (2.4 mg/kg) was conducted in adult Sprague Dawley (SD) rats (n = 8). An optimized liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the analysis of plasma metoprolol to evaluate its pharmacokinetics. In vitro, the rat liver microsomes were employed to assess the effect of Ginkgo tablets on the metabolic stability of metoprolol and the activity of Cytochrome P450 2D6 (CYP2D6). RESULTS: The developed LC-MS/MS method was demonstrated of high sensitivity, accuracy, and precision. When co-administered with Ginkgo tablets, it increased the area under the curve (AUC, 59.01 ± 10.11 vs. 39.19 ± 10.21 μg/mL × min), the maximum plasma concentration (C(max), 461.72 ± 44.64 vs. 276.35 ± 118.09 ng/mL), and the half-life (t(1/2), 302.83 ± 91.52 vs. 262.34 ± 111.12 min) of metoprolol in rats and reduced the clearance rate (0.346 ± 0.057 vs. 0.539 ± 0.145 L/min/kg). In vitro, Ginkgo tablets improved the metabolic stability of metoprolol and suppressed the activity of CYP2D6 in a concentration-dependent manner with the IC(50) value of 11.17 μM. CONCLUSION: Co-administration of metoprolol with Ginkgo tablets resulted in increasing its systemic exposure through inhibiting CYP2D6 activity.