How alprostadil works
Alprostadil is a synthetic form of prostaglandin, a naturally occurring chemical in the body. It works by causing blood vessels to expand (vasodilation), increasing blood flow. When this is administered to the penis the increased blood flow results in an erection.
How alprostadil is given
Alprostadil can be applied:
directly to the penis by injection (under the trade names Caverject or Viridal Duo)
as a pellet that can be inserted with an applicator into the tip of the penis (known as MUSE - Medicated Urethral System for Erections)
as a cream that can be inserted with an applicator into the tip of the penis (known as Vitaros - urethral alprostadil cream)
Side effects and contraindications
Side effects of Caverject and Viridal Duo can include pain in the penis or groin and bleeding in the tissue around the injection site. Less frequently, the erection may not subside for several hours. This is known as priapism and can be uncomfortable and, without medical attention, may result in tissue damage in the penis.
A side effect with MUSE and Vitaros is a burning feeling or irritation at the end of the penis. The partner may also experience similar pain after penetrative sex and oral sex should be avoided with a man using them. They shouldn't be used if the partner is pregnant.
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Last updated: August 2018
Last reviewed: August 2018
This page will be reviewed within three years