Vardenafil-d5 is a deuterium-labeled phosphodiesterase inhibitor that is selective for PDE5 and PDE1 (IC50 = 0.7 and 180 nM, respectively). Verdenafil is closely related to sildenafil and tadalafil in structure as well as function. Inhibition of PDE enzymes prevents the breakdown of secondary messenger molecules, prolonging signal transduction and its subsequent effects. This compound is useful in kinetic isotope effect studies and as an internal standard in NMR experiments.
