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Too much of a good thing: The 4-hour erection

By Diane Mapes

We've all heard those warnings at the end of Viagra, Cialis or Levitra commercials about contacting your doctor if you have an erection that lasts longer than four hours (prompting many a joker to declare, "the hell with the doctor, I'm calling my friends!").

But priapism, a prolonged erection unaccompanied by sexual desire and unaffected by orgasm, is actually no laughing matter.

"A prolonged erection is usually painful," says Dr. Ira Sharlip, clinical professor of urology at the University of California at San Francisco and spokesperson for the American Urological Association. "Men usually know something's wrong even if they've never heard of this condition, and almost always come in for care because of the pain. There are some men who don't want to go to the doctor or an emergency room, but they should know that it's a potentially serious condition which can result in permanent erectile dysfunction if it's not taken care of."

Named for Priapus, the Greek god of fertility who sported an oversized, eternally-erect penis (so large, in fact, he used it to frighten away anyone who tried to plunder his gardens), priapism brought on by erectile dysfunction drugs is extremely rare.

"The [Food and Drug Administration] requires a warning in the package insert because of the potential complication, but I've been prescribing Viagra for 10 years to many thousands of men and have never seen a case," says Sharlip, who maintains a private urology practice in San Francisco. "It does happen even in men who aren't taking erection drugs – I've taken care of the problem at the emergency room at the medical center where I work — but  it's really rare. So rare, that I don't discuss this as a potential complication with my patients."

Image: Body Odd

Rough statistics from the FDA's adverse event reporting system (AERS) regarding the erectile dysfunction (ED) drugs Viagra, Cialis and Levitra show a total of just 93 cases of prolonged erection greater than four hours or painful erection greater than six hours (priapism) in all of 2007 — 74  for Viagra, three for Levitra and 16 for Cialis. According to the FDA, physicians are encouraged to report suspected adverse events, although the event may be related to an underlying disease, another drug or simple chance.

Priapism is much more commonly seen in conjunction with penile injection therapy (an alternate treatment for ED), blood diseases such as leukemia or sickle-cell anemia, injury or trauma to the penis, spinal cord injuries, or as a side effect to certain drugs such as the antidepressant trazadone. The condition is found in all age groups, including children (usually in association with leukemia). There are also extremely rare cases of priapism in females (known as clitorism). A recent msnbc.com column dealth with a 70-year-old man who thought he had a form of priapism.

To understand priapism, it's important to first understand the mechanics of an erection, which occurs when the blood vessels of the penis relax and open. ED drugs like Viagra don't trigger erection — you  need some kind of sexual stimulation for that —  but  they definitely set the stage by increasing enzyme actions in the erection chambers. Once the stage is set (via a little blue pill and a few soft lights, a hint of lingerie, and the musical stylings of Barry White), the spongy tissues along the length of the penis fill with blood and harden and the veins leaving the penis constrict.

Unfortunately, in the small percentage of men suffering from priapism, the system goes haywire and they're unable to get rid of their erection once it shows up. In a nutshell, blood can get in but it can't get out, a condition that sounds a bit like one of those old Roach Motel commercials, but is actually quite serious.

"If an erection is left in place for more than 12 hours, damage to the tissue in the erection chambers can occur," says Sharlip. "It can be a cause of serious erectile dysfunction. They may be able to get a partial erection in the future, but not a full erection."

Worse yet, there have been reported cases of permanent penile injury thanks to untreated priapism. Dr. Christopher Steidle, author of "The Impotence Sourcebook," details the case of "H.A.," a medical professional who, after reading about the treatment of erectile dysfunction with penile injections, injected himself with an excessive dose.

Unfortunately, he then developed priapism, but was so embarrassed he went for seven days before seeking medical help. According to Steidle, "the resulting erection was unsalvageable, and the patient was left with a penis that was less than an inch long." 

If you should find yourself with a four-hour erection on your hands, the sooner you seek treatment (which usually involves either draining the blood from the area with a needle or doing the same thing with a surgical shunt), the better off your penis will be.

As for those who would make light of what doctors consider a serious medical emergency?

"I suppose it's funny to talk about," says Sharlip.  "But it's not funny when it happens to you."