Product Name:Vardenafil (Leviitra)
Description:Vardenafil is a new PDE5 inhibitor launched for oral treatment of male erectile dysfunction and it has significant structural similarity with sildenafil (Viagra), which was the first PDE5 inhibitor introduced in 1998 for this indication. Vardenafil is synthesized in three steps starting with a cyclization reaction of 2-ethyoxybenzamidine with 2-butyramidopropionic acid and ethoxyallyl chloride to construct the imidazotriazine ring system, followed by sulfonation to the corresponding sulfonyl chloride and subsequent condensation with 1-ethylpiperazine. The potency of PDE5 inhibition by vardenafil is -10 times greater than that of sildenafil . Vardenafil is typically administered in single doses of 10 and 20 mg. The time to reach maximum plasma concentration is 0.75 h, which is slightly shorter than those of sildenafil and tadalafil, and the half-life is 4-5 h. Although it is almost completely absorbed following oral administration, the mean absolute bioavailability of a 10 mg dose is -15%, resulting from extensive first pass metabolism. Vardenafil is metabolized in the liver primarily by CYP3A4 and is eliminated mainly in feces.