1. ¹Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
2. ²Clinical Pharmacology and Therapeutics Division, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
3. ³Clinical Pharmacology and Pharmacokinetics, Merck KGaA, Darmstadt, Germany

Correspondence: Dr B Meibohm, Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, 874 Union Avenue, Suite 5p Memphis, TN 38163, USA. E-mail: bmeibohm@utmem.edu

Received 15 June 2006; Revised 29 July 2006; Accepted 22 August 2006; Published online 21 September 2006.

Abstract

Differences in clinical pharmacology of the currently marketed phosphodiesterase (PDE)5 inhibitors sildenafil, vardenafil and tadalafil are largely determined by their pharmacokinetic (PK) properties and their PDE5 inhibitory activity profile. This review outlines the basic concepts of pharmacokinetics and pharmacokinetic pharmacodynamic (PK/PD) relationships and their relevance to dose selection and applied pharmacotherapy. It is followed by a detailed comparative discussion on the pharmacokinetics and exposure–response relationship of the currently available PDE5 inhibitors, including known drug–drug interactions and dosage adjustments in special populations. The review is aimed at providing a critical assessment of the pharmacokinetics of PDE5 inhibitors, which may assist clinicians in tailoring drug and/or treatment regimens to the unique needs of each individual patient with erectile dysfunction.