Drug Therapy for ED: Self Injection

Self-injection therapy is one of several available options for treating impotence. It requires that a man or his partner use a tiny needle to inject a small amount of medicine directly into the side of the penis. The injections are relatively painless and create an erection that begins about 5 to 15 minutes after the injection, and lasts from 30 to 120 minutes.

Not all patients respond to this type of treatment. Still, about 70 percent of men find that they achieve satisfactory erections with injections. A doctor can generally teach a person to do the injections in one or two office visits. Patients will have to return for follow-up visits, particularly at the beginning of the treatment process, to see if the drugs used need to be changed or the dosages adjusted.

The drugs typically used for injection therapy include Prostaglandin (PGE-1 or Prostin or Alpoprostadil or Caverject), papaverine hydrochloride and phentolamine (Regitine).

The FDA has approved all of these drugs for other medical uses, but only prostaglandin has been approved specifically for treating impotence. Papaverine and phentolamine have not yet been approved for treating impotence, even though they were the first ones used for injection therapy. Nevertheless, urologists have gained considerable experience over the past decade with all three of these drugs, and all are now considered safe for injection therapy.

All medications have potential risks and side effects. The drugs used in self-injection therapy are still technically considered experimental. Some men complain of dizziness, heart palpitations and/or a flushed feeling when using these medications. And there is a small chance of infection and the possibility of bleeding or bruising during injection.

One of the more common risks of injection therapy is prolonged erection or priapism: an erection of more than 4 hours. Priapism only happens in a small percentage of patients but may require a visit to the doctor or emergency room to receive medication to counteract the self-injection medication and relieve the erection. Men need to be aware that any erection that lasts longer than 4 hours needs to be treated by a physician.

Another complication is the possible development of permanent scarring within the penis. Scarring is generally seen in patients who use the drugs too often. Consequently, self-injection therapy should be limited to once every four to seven days, depending on what medication is used and how a man responds to the initial treatment. Scarring can make obtaining erections even more difficult, even with additional medication. If the scarring is severe, later placement of a penile prosthesis can be difficult.

Advantages and Disadvantages of Self-Injection Therapy

Self-injection therapy can be used anytime and only involves a small amount of preparation. It creates an erection that is very similar to the body's own spontaneous erection, and generally lasts long enough for successful and pleasing intercourse. Self-injection therapy also does not interfere with orgasm or ejaculation.

This type of treatment does not involve surgery and is only minimally painful. Though self-injection therapy can cost up to $8 to $10 per injection, it is much less expensive than surgery.

Not all men are good candidates for self-injection therapy. Some men do not develop adequate erections, while others may get erections that last longer than desired. Self-injection therapy requires a man or his partner to inject medication directly into the penis. Follow-up visits to the doctor are necessary, especially early on. And the cost can be prohibitive for some people.

Drug Therapy: Urethral Suppositories (MUSE)

Uretheral suppositoriers (MUSE) is another drug treatment for impotence. It is based on the finding that the urethra (the tube in the penis through which urine and semen flow) can absorb certain medications into the surrounding tissues, creating an erection. Muse urethral suppositories use prostaglandin E1 (alprostadil), the same medication used in self-injection therapy.

An erection usually begins within 5 to 10 minutes after administering a pre-filled muse dosage. The erection lasts approximately 30 to 60 minutes, though this can vary from person to person.

The most common side effects associated with muse are an aching in the penis, testicles, legs and in the area between the scrotum and the rectum, a warmth or burning sensation in the urethra, redness of the penis due to increased blood flow, and minor urethral bleeding or spotting due to improper administration.

Publication Review By: David M. Kaufman, M.D., Stanley J. Swierzewski, III, M.D.

Published: 09 Jun 1998

Last Modified: 14 Sep 2015