Tadalafil, sold under the brand name Cialis among others, is a medication used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. It is taken by mouth. Onset is typically within half an hour and the duration is up to 36 hours.
Common side effects include headache, muscle pain, flushed skin, and nausea. Caution is advised in those with cardiovascular disease. Rare but serious side effects include a prolonged erection that can lead to damage to the penis, vision problems, and hearing loss. Tadalafil is not recommended in people taking nitrovasodilators such as nitroglycerin, as this may result in a serious drop in blood pressure. Tadalafil is a PDE5 inhibitor which increases blood flow to the penis. It also dilates blood vessels in the lungs, which lowers the pulmonary artery pressure.
Tadalafil was approved for medical use in the United States in 2003. It is available as a generic medication. In 2020, it was the 261st most commonly prescribed medication in the United States, with more than 1 million prescriptions.
Tadalafil is used to treat erectile dysfunction, benign prostatic hyperplasia, and pulmonary arterial hypertension. In the US, tadalafil (as Cialis) is indicated for the treatment of erectile dysfunction and the signs and symptoms of benign prostatic hyperplasia; and (as Adcirca) for the treatment of pulmonary arterial hypertension to improve exercise ability.
A meta‐analysis found that tadalafil is an effective treatment for lower urinary tract symptoms due to prostatic hyperplasia and that such treatment had a low rate of adverse effects. Tadalafil is FDA-approved for men as a therapy to treat and prevent symptoms of benign prostatic hypertrophy, such as urinary urgency, hesitancy, weak stream, dribbling, and incontinence. Tadalafil was found to have similar benefits for lower urinary tract symptoms as the usually prescribed tamsulosin.
Tadalafil is approved in the United States, Canada, and Japan to improve exercise ability in people with pulmonary arterial hypertension.