Find patient medical information for Tadalafil (Cialis, Adcirca, and others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. Tadalafil is a generic drug prescribed for erectile dysfunction and other conditions. Learn about the drug’s dosages, form, strengths, and more. What is tadalafil, and what is it used for? Tadalafil is an oral drug that is used for treating impotence, or erectile dysfunction (the inability to attain or maintain a penile erection), and benign prostatic hyperplasia (BPH). When taken as needed, the typical dose is 10 mg at least 30 minutes before sexual activity, which can be increased to 20 mg if necessary. The maximum recommended dose is 20 mg per day. Tadalafil is also approved to treat BPH symptoms, such as difficulty urinating. Tadalafil is in a class of medications called phosphodiesterase (PDE) inhibitors. It works to treat erectile dysfunction by increasing blood flow to the penis during sexual stimulation. Tadalafil is prescribed for benign prostatic hyperplasia, erectile dysfunction, and pulmonary arterial hypertension. Learn about side effects and more. Tadalafil increases blood flow to particular areas of the body and is used to treat erectile dysfunction. Learn about side effects, interactions and indications. Medscape - Erectile dysfunction, pulmonary arterial hypertension-specific dosing for Adcirca, Cialis (tadalafil), frequency-based adverse effects, comprehensive interactions, contraindications. Tadalafil 20 mg is the maximum as-needed dose for ED. Learn about its uses, how long it lasts, side effects, and how to save on your prescription.