Despite what the commercials claim oral agents are not going to work for all patients. Some patients are not able to use these drugs due to other medications that they use which could result in a serious adverse event. However, the good news is that other alternatives exist for these.
Medications that are injected directly into the penis preceded the use of oral agents by more than 25 years. At the 1983 meeting of the American Urological Association, the British physiologist Gile Brindley shocked the audience when he revealed an erection that was created by a self injection of phenoxybenzamine.
In the era that followed, many urologists prepared various cocktails of drugs that were injected into the corpora cavernosa of the penis. These mixtures usually consist of varying doses of papaverine, phentolamine, and prostaglandin E1. The vasodilatory properties of these drugs help to induce an erection.
These substances were in widespread use prior to the introduction of the oral agents that are now commonly used, until a patent-infringement lawsuit was introduced that questioned the ability to use these combinations without paying a royalty to do so. As a result their use fell out of favor; however in 1995, Lilly introduced Caverject which supplanted the use of these agents.
Caverject (alprostadil- prostaglandin E1) is a potent vasodilator that also has an indication for usage in patients with congenital heart disease. The drug is now supplied in a pre-mixed syringe. The patient dials up the correct dosage of the medication and self injects the drug in the lateral aspect of the penis with a very small needle.
After a brief training session, patients can easily inject themselves up to 3 times weekly. The injections are fairly well tolerated and can be associated with minor side effects such as pain or irritation at the injection site. Priapism, an erection that lasts longer than 4 hours has been reported with the use of these substances. The formation of fibrous tissue within the penis has also been reported with the long term use of these substances.
Published On: December 15, 2006