Multiple transport mechanisms involved in the intestinal absorption and first-pass extraction of fexofenadine,

Abstract

In this in vivo perfusion study verapamil increased the bioavailability of fexofenadine. Because the permeability, which is a direct measure of intestinal transport, was unchanged, we suggest that the major reason for this effect was decreased first-pass liver extraction of fexofenadine. The most plausible mechanism is either decreased organic anion transporting polypeptide-mediated sinusoidal uptake or P-glycoprotein-mediated canalicular secretion of fexofenadine, or both.