Intestinal secretion of intravenous talinolol is inhibited by luminal R-verapamil*

Intravenously administered talinolol is actively secreted into the human small intestine. This secretion is reduced by the intraluminal supply of the P-glycoprotein modulating drug R-verapamil. This gives further rationale for P-glycoprotein-mediated intestinal drug secretion as a cause for incomplete oral bioavailability and for drug interactions during intestinal absorption.