The penis consists of two erection chambers lined by an elastic wall called the tunica albuguinea. During a normal penile erection, as blood enters the erection chambers, the tunica is stretched both wider and longer. In men who have Peyronie’s Disease, the elasticity of the wall has decreased leading to erections that are deformed such as penile narrowing, penile length loss and/or penile curvature. Treatments for Peyronie’s Disease include vacuum stretching, topical agents, oral agents, intralesional injection therapy and surgery.
Intralesional administration of drugs can be performed to improve the elasticity of the scar or plaque area affected by Peyronie’s Disease. The goal of intralesional therapy is to pharmacologically soften the inelastic scar or plaque area. There are several intralesional drugs including alpha-2beta (Intron A), verapamil, and collagenase. The injected drug acts to indirectly (interferon and verapamil) or directly (collagenase) activate collagenase. Collagenase acts to digest the collagen in the scarred area.
Interferon is typically 2.5 – 5 million units per administration, typically repeated every other week for a total of 6 administrations over 3 months. The drug is typically prescribed in 10 million unit vials in a package of 3 vials. Some patients prefer to perform the 6 adminstrations over a 2 week period instead of extending the treatment for 3 months.
The major side effect of each use of intralesional interferon is flu-like symptoms including shivering, nasal stuffiness and fever therefore patients are advised to take NSAIDS (non steroidal anti-inflammatory drugs) 2 hours before and 6 hours after interferon administration. The flu-like symptoms are transient and only last several hours.
While you are lying supine on an examining table a small needle will be inserted under the skin of your penis to inject a numbing medication. After 20 minutes, when the penile shaft is numb, the penis will be cleaned with a proviodine solution to sterilize the area. The interferon will be administered into the regions of the Peyronie’s plaques. Following administration your penis will be wrapped with an elastic dressing and you will be instructed to compress your penis tightly for 10 minutes to prevent bruising. The compression bandage on the penis should be removed approximately two hours after it was applied.
A double blind placebo controlled study has shown approximately 55% of men who use interferon will report improvement in Peyronie’s disease associated symptoms such as pain during erection, curvature, and penile shortening.