Self-Injection Therapy Another method for treating erectile dysfunction is self-injection drug therapy. It requires that the man or his partner use a tiny nee- dle 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 minutes to 2 hours. No foreplay is needed.
Drugs used for self-injection therapy include a prostaglandin (a synthetic fatty acid) called alprostadil, papaverine hydrochloride, and phentolamine in combi- nation with papaverine. Each of these drugs creates an erection by relaxing smooth muscle tissue and widening the major artery to the penis, which enhances blood ﬂow to the penis.
Originally, the US Food and Drug Administration (FDA) approved these drugs for other medical purposes, but only the prostaglandin drug has been approved speciﬁcally for treating erectile dysfunction. Papaverine and phento- lamine have not yet been approved for treating erectile dysfunction, even though they were the ﬁrst drugs used experimentally for injection therapy. However, they are available and prescribed for medical reasons other than the FDA- approved use. Urologists have gained considerable experience with all three of these drugs, and all are considered safe for self-injection therapy.
Not all men respond to this type of treatment. Apart from the fact that most men have trouble injecting a needle into their penis, self-injection therapy cannot be used by men with certain heart or liver diseases. Of those who can take the injections, some do not respond by developing good erections, while others may get erections that do not go away and require a counterinjection to soften them. Still, about 70 percent of men ﬁnd that they achieve satisfactory erections after self-injections. Generally, a doctor can teach a person to do the injections in one or two ofﬁce visits. The men are asked to return for follow-up visits, particularly at the beginning of the treatment process, to see if changes are needed in the type of drug used or its dosage.
All medications used in self-injection therapy have both potential risks and side effects. Some men have experienced dizziness, heart palpitations, 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 risks of self-injection therapy is prolonged erection or priapism— an erection that lasts more than 4 hours. Priapism occurs in only a small per- centage of men, but it requires a trip to a hospital emergency department to receive medication to counteract the self-injection and relieve the erection. Men should know that any erection that lasts more than 2 hours needs to be treated by a physician to prevent damage to the penis.
Another potential risk, particularly for those who use self-injected drugs often, is the possibility of permanent scarring inside the penis. For this reason,
doctors advise that self-injection therapy be limited to once every 4 to 7 days, depending on what medication is used and how a man responds to the initial treatment.
Self-injection therapy has the following advantages:
• It can be used anytime and involves only a small amount of preparation.
• It creates an erection that is very similar to a natural erection.
• The erection generally lasts long enough for successful and satisfying inter- course.
• It does not interfere with orgasm or ejaculation.
• It does not involve surgery and is only minimally painful.
• The drug costs $8 to $10 per injection, which is much less than surgery. (Sildenaﬁl currently costs about $8 to $10 per pill; see page 154.)
Urethral Suppositories In 1997 the FDA approved an alternative form of the drug alprostadil. The product is a single-use applicator ﬁlled with the drug. The user inserts the applicator about an inch into the urethral opening of the penis, where the drug is released, absorbed by the urethra, and transported to the sur- rounding tissues. An erection begins within 8 to 10 minutes and may last as long as 30 to 60 minutes. These times vary from one person to another.
The most common side effects associated with urethral suppositories are aching in the penis, testicles, legs, and the area between the scrotum and the rec- tum; a warm or burning sensation in the urethra; redness of the penis due to increased blood ﬂow; and minor urethral bleeding or spotting, usually caused by improper application.