Erectile dysfunction (ED) affects more than 150 million men and their partners throughout the world. Sildenafil, the first oral phosphodiesterase-type 5 (PDE-5) inhibitor approved for the treatment of ED, has led to the discovery of 2 more products in this class, with tadalafil being the latest. Tadalafil has proven to be well tolerated in various clinical studies and has demonstrated effectiveness in men with mild to severe ED, regardless of severity, etiology, or age. One major characteristic that may distinguish tadalafil from other oral PDE-5 inhibitors is its extensive duration of effect. Tadalafil has a therapeutic duration of up to 36 hours that may allow patients to engage in sexual activity at their own convenience rather than in a limited time period. This, along with other clinical and practical advantages, should make tadalafil an attractive alternative to currently available treatments options. This article summarizes the pharmacology, pharmacokinetics, adverse effects, and clinical efficacy of tadalafil.
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