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On call: Trazodone and priapism

On call

Trazodone and priapism

Q. I am 47 years old and I've always been healthy. My main problem is insomnia. Sleeping pills don't work well, and they make me feel groggy. Finally, my doctor gave me a prescription for Desyrel, and he seems to have hit the bull's-eye. I've been sleeping much better and haven't noticed any side effects. But my pharmacist warned me about abnormal erections. Is it a serious concern?

A. Trazodone (Desyrel) is an antidepressant, but like many medications, it has other "off-label" uses: A physician can prescribe the medication for a purpose not specifically approved by the FDA. Indeed, trazodone can be very helpful for promoting sleep, even in people who are not depressed. Like all medications, though, it can have side effects. Among the most common are loss of appetite, dry mouth, and constipation, but they are relatively infrequent.

Trazodone can indeed cause abnormal erections, but it's a rare side effect and usually occurs during the first month of therapy. The problem is called priapism, a prolonged and painful erection that does not resolve following ejaculation. Trazodone can cause low-flow priapism, in which the veins of the penis are abnormally narrowed so the extra blood that enters the penis to produce an erection cannot exit normally and the organ remains erect.

Low-flow priapism can result from oral medications (your trazodone, chlorpromazine, hydralazine, and others), drugs that are used for erectile dysfunction (the ED pills and alprostadil injections), alcohol, and drugs of abuse such as cocaine. It can also be a complication of sickle cell anemia. Most often, however, it occurs out of the blue, either after sex or when a spontaneous nighttime erection fails to resolve.

Priapism is painful, and without treatment it may last for 4 to 24 hours. It can also cause permanent damage. To avoid that, men with the problem should apply ice to the erection, take a pain reliever, and head to the emergency ward. Urologists can usually control the problem by aspirating blood from the engorged penis and injecting an artery-narrowing drug directly into the penis to reduce the amount of blood entering the organ.

The other type of priapism results from trauma to the penis. High-flow priapism is best diagnosed by duplex ultrasound and is usually treated by arterial embolization, which blocks the abnormal arterial channels that carry excessive amounts of blood to the penis.

High-flow priapism is rare, and low-flow priapism is very uncommon. You should understand the problem and know what to do if it occurs. But since it's so uncommon, you can take your trazodone at bedtime without losing any sleep over it.

— Harvey B. Simon, M.D. Editor, Harvard Men's Health Watch

Last updated:	September 05, 2008