The clinical pharmacokinetics of phosphodiesterase-5 inhibitors for erectile dysfunction.

Differences in the clinical pharmacology of the 3 currently available oral phosphodiesterase-5 (PDE5) inhibitors, sildenafil, vardenafil, and tadalafil, are largely determined by their clinical pharmacokinetics as well as their PDE inhibitory activity profile. This review comparatively discusses the major characteristics of the pharmacokinetic profile of all 3 PDE5 inhibitors, including bioavailability and rate of absorption, Biopharmaceutical Classification System categorization, elimination mechanisms, and metabolic profile including active metabolites, as well as the drug-drug interaction potential and modification of pharmacokinetic properties under selected physiologic and pathophysiologic conditions. The review is aimed at providing comparative clinical pharmacology data to allow for scientifically rational, evidence-based prescribing and dosing decisions regarding the clinical use of these medications for the treatment of erectile dysfunction.