Men with erectile dysfunction, or impotence, are treated with generic Tadarise. Tadalafil, a phosphodiesterase type 5 inhibitor, is the ingredient in Tadarise tablets, which are prescribed to treat impotence and erectile dysfunction in men. The generic form of Cialis, Tadarise, has 20 mg of tadalafil. Take the medication with or without food, and with a glass of water. With a glass of water, take the medication. Take it an hour before having any sexual relations.  Without a prescription from a doctor, never use the medication.