Dabigatran Etexilate and Digoxin: Comparison as Clinical Probe Substrates for Evaluation of P-gp Inhibition.

P-glycoprotein (P-gp) inhibition is part of routine drug-drug interaction (DDI) investigation in drug development. Selection of P-gp clinical probes depends on selectivity, sensitivity, and comedication relevance. Traditionally, this DDI was assessed clinically using digoxin, primarily because of safety concerns. Digoxin is neither a specific nor sensitive P-gp probe. Dabigatran etexilate (DE) has been proposed as an alternative to study intestinal P-gp inhibition. Comparison of digoxin and DE reveals key aspects of their suitability and limitations as P-gp probes.