is a prostaglandin, which is used in the treatment of erectile dysfunction and has vasodilatory properties. Target: Prostaglandin Receptor Prostaglandin E1 (PGE1), known pharmaceutically as alprostadil, is a prostaglandin. It is a drug used in the treatment of erectile dysfunction and has vasodilatory properties. In healthy humans, prostaglandin E1 is biosynthesized "on demand" at its intended site of action from dihomo-γ-linolenic acid. Alprostadil is a naturally occurring prostaglandin used in the treatment of infants with congenital heart defects to maintain the patency of the ductus arteriosus until palliative or corrective surgery can be performed. In infants with defects restricting pulmonary blood flow (cyanotic), alprostadil improves arterial blood oxygenation. In infants with defects restricting systemic blood flow, alprostadil improves arterial blood pH, urine output, and femoral arterial pulses. Alprostadil is administered by continuous intraarterial or intravenous infusion, usually at a starting dose of 0.1 microgram/kg/min, with maintenance doses as low as 0.002 microgram/kg/min.