The rationale for prostaglandin E1 in erectile failure: A survey of worldwide experience

Purpose: Prostaglandin E1 (PGE1, alprostadil) is used worldwide for self-injection therapy in erectile failure and was recently officially approved for this purpose in the United States and most European countries. Therefore a comprehensive overview on biochemistry, pharmacology and therapeutic results of PGE1 is provided. Materials and Methods: The relevant literature on PGE1 was reviewed along with personal experience with 4,577 patients during a 7-year period. PGE1 was compared to other vasoactive drugs, such as papaverine, the mixture of papaverine and phentolamine or linsidomine alone. Results: In Europe PGE1 was officially approved for the therapy of peripheral arterial occlusive disease of the lower limbs in 1984. The drug has direct relaxing effects on smooth muscle cells of vessels and cavernous bodies, shows inhibitory effects on platelet aggregation, on low-density lipoprotein entry into the vascular wall and on presynaptic noradrenaline release and, therefore, it prevents the progress of atherosclerosis. In erectile failure PGE1 shows a response rate of more than 70% and, compared to papaverine with phentolamine, a considerably lower risk of priapism (0.35% versus 6%, respectively) as well as of local fibrotic complications. Except for rare cases of blood pressure decrease, no systemic side effects were observed after intracavernous injection of PGE1. Conclusions: For self-injection therapy, PGE1 presently represents the most efficacious and safest drug. Ongoing trials with topical and especially intraurethral PGE1 are promising and may offer less invasive therapies in the near future.