The naturally occuring prostaglandin E1 (PGE1) which displays a variety of pharmacologic actions. Alprostadil is a potent vasodilator agent that increases peripheral blood flow, inhibits platelet aggregation, and induces bronchodilation. Used in the treatment of erectile dysfunction, this agent produces corporal smooth muscle relaxation by binding to PGE receptors, resulting in the activation of adenylate cyclase and the subsequent accumulation of 3'5'-cAMP. OR A drug that is used to treat impotence (inability to have an erection) and is being studied in the treatment of sexual problems in men who have had surgery for prostate cancer. It is a type of vasodilator. Also called PGE1 and prostaglandin E1.