Green tea ingestion greatly reduces plasma concentrations of nadolol in healthy subjects.

This study aimed at evaluating effects of green tea on pharmacokinetics and pharmacodynamics of the β-blocker nadolol. Ten healthy volunteers received a single oral dose of 30 mg nadolol with green tea or water after repeated consumption of green tea (700 mL/day) or water for 14 days. Catechin concentrations in green tea and plasma were determined. Green tea markedly decreased Cmax and AUC0-48 of nadolol by 85.3% and 85.0%, respectively (P < 0.01) without altering renal clearance of nadolol. Nadolol effects on systolic blood pressure were significantly reduced by green tea. [(3)H]Nadolol uptake assays in HEK293 cells stably expressing OATP1A2 or OATP2B1 revealed that nadolol was a substrate of OATP1A2 (Km=84.3 μM), but not of OATP2B1. Moreover, green tea significantly inhibited OATP1A2-mediated nadolol uptake (IC50=1.36%). These results suggest that green tea reduces plasma concentrations of nadolol possibly in part by inhibition of OATP1A2-mediated uptake of nadolol in the intestine.Clinical Pharmacology & Therapeutics (2014); accepted article preview online 13 January 2014 doi:10.1038/clpt.2013.241. PMID: 24419562 [PubMed - as supplied by publisher]
Source: Clinical Pharmacology and Therapeutics - Category: Drugs & Pharmacology Authors: Tags: Clin Pharmacol Ther Source Type: research