How Caverject and Penile Injections Work

Health Professional

When diet and health modifications have failed to alleviate erectile dysfunction and the patient has tried all forms of the oral medications, the patient must then be counseled on the remaining types of therapies, including the prostaglandin family of medications. These are medications that act locally in the penis to give an erection. This differs from the pill or "Viagra" type of medications that require the central nervous system (i.e., the brain) to tell them to work. This type of medication comes in two preparations and can be delivered in two routes (injection or penile suppository).

The first route is by injection into the penis. The common brand name for this medicine is Caverject or alprostadil (generic). This medication also comes in various strengths as the pills do. A lot of patients do not like this option for obvious reasons. It does require the injection of the medicine into the base of the penis. The medication is dispensed in a small vial with a needle, or in a syringe that is already loaded. The first injection, or the trial run, must be performed at the urologist's office under direct supervision. This is done to assure that the patient understands the techniques involved in the administration, and to make sure the patient does not develop a prolonged, painful erection known as "priapism."

The newer preparations are pre-loaded which makes the procedure much easier. The patient either dials the wheel on the pre-loaded device or draws up the necessary amount into the syringe. An alcohol swab is then used to clean the base of the penis (the area away from the tip). The injection must occur on the side of the penis as well. Care is taken to avoid any large veins on the surface of the skin of the penis. After the injection, pressure can be applied with the patient's finger to make sure the bleeding has stopped. There is usually little bleeding involved with the injection.

Once the injection is given, manual manipulation (similar to masturbation) of the penis must be performed to massage the medication throughout the penis. This process may take fifteen to twenty minutes before signs of an erection occur. Once the erection is firm enough, the patient can engage in sexual activity.

After orgasm and ejaculation, the body releases chemicals that cause the penis to be soft. Even in the setting of recent injection, this may cause the penis to soften. In some patients, one injection may allow several episodes of sexual activity in a single session; however, this depends on the patient's baseline erectile dysfunction. Patients should not use more than one injection per twenty-four hour period.

A downside to this treatment for ED is that the administration or injection may break up the flow of the sexual encounter. For example, the couple may be in the middle of foreplay, and the man must then stop to inject. This can sometimes be overcome with injection prior to foreplay.