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This report originally appeard on the Sapient Health Network web site, which later became WebMD.
It is an early look at Viagra; before the drug was approved.

Brighter Future Awaits Men with Impotence Caused by Cancer Treatment

Jan. 1998

Exclusive to SHN 

Prostate cancer treatment often damages a man's sex life. This is an unpleasant reality. But experts stress men do not need to accept impotence. Exciting new options on the horizon and a solid lineup of available treatments give hope for combatting one of treatment's most unwelcome side effects. 

The FDA is considering approval of the first oral pill to treat impotence. Many observers expect sildenafil (manufactured under the brand name Viagra) to be on the market within months. When it becomes available, the pill is likely to be the first treatment choice for most men. 

"It's going to go right up front," predicts Richard Babaian, M.D., of the M.D. Anderson Cancer Center in Houston. 

That encouraging outlook is echoed by Drogo Montague, M.D., at the Cleveland Clinic."It clearly does appear to be an effective drug," Dr. Montague says. For instance, in one study 10 out of 12 men reported improvements in their ability to achieve an erection. 

Sildenafil is similar to drugs that now must be injected. It works by preventing the body from breaking down a chemical key to controlling the amount of blood retained in the penis. As a result, more of this chemical remains in circulation, thus keeping blood in the penis. However, it seems men need to have at least some partial erectile function in order to be helped by sildenafil. 

Studies that focus on men who have had prostate cancer treatment are still underway. "How effective it's going to be in this category of patients, I think it's still too early to tell," cautions Dr. Montague, "but it's certainly a possibility." 

Though the success rates for prostate cancer patients are still being determined, Dr. Babaian expects sildenafil to become a popular treatment as soon as it is available. "Because it's going to be so simple, just pop a pill, it will become the primary treatment for impotence," he predicts. 

Two other impotence pills are also in the pipeline. Phentolamine (under the brand name Vasomax) is a reformulation of a drug already available in injectable form. The third drug, apomorphine (Spontane), works in the brain, so experts say it is likely to be most useful to men with psychogenic forms of impotence, rather than problems with a purely physical source, such as side effects of cancer treatment. 

Until pills hit the market, most prostate cancer patients seeking treatment for impotence are offered proven methods including vacuum pump devices, injected or inserted drugs, and penile implants. An examination of the problem itself can heighten understanding of these treatments. 

While impotence rates vary with the type of treatment, the extent of the prostate cancer, and the age and other characteristics of the patient, a recent review of published studies concluded that impotence affects almost 60 percent of prostate cancer patients receiving surgery, and about 30 percent of men treated with radiation. 

Impotence is often caused by damage to nerves involved in controlling erections. The efficacy of "nerve sparing" operations at restoring potency is still being debated. Many doctors are also concerned that by limiting the extent of surgery, they could miss some cancer cells, thus putting the patient's life at greater risk. 

Experts say it's important for men to understand that impotence means it is difficult or impossible for a man to have an erection, but does not mean a man cannot experience any sexual enjoyment. 

"Even though they've had a prostatectomy, and even though they are unable to have an erection, they can still have an orgasm," Dr. Babaian points out. "They will not ejaculate, obviously, but they are still able to have pleasure through a sexual experience." 

Most doctors start by suggesting men try a vacuum device, since it is the least expensive ($400 to $500) and least invasive method available. This is a mechanical solution to what is primarily a mechanical problem: the failure of the penis to retain enough blood at sufficient pressure to maintain an erection. The device consists of three main parts: a tube, a hand-pump, and an elastic ring. The man inserts his penis into the tube and uses the pump to pull air out of the tube. The negative pressure draws blood into the penis. He then slides an elastic ring over the base of his penis to hold the blood in place. The procedure is safe, takes only a couple of minutes, and lasts for about half an hour. 

"It seems to work okay, but it's a little awkward," prostate cancer patient Teddy Dean says of the vacuum device. 

Though vacuum devices usually work, many men don't try them or stop using them, in part because they say the device, and its intrusion, interfere with sexual spontaneity. 

"I got one of those vacuum pumps, but I didn't like it," says prostate cancer patient David Schmidt, who felt the vacuum device incompletely responded to his sexual needs. "I wasn't comfortable with it," he says. He and his partner have found other ways of expressing their sexuality. 

For men who do want to pursue alternatives to a vacuum pump, the next step can initially intimidate -- using a fine needle (similar to the ones diabetics use to inject insulin) to inject drugs into the penis. These medicines include papavarine, phentolamine, and prostaglandin E1. 

"Usually the first reaction is: 'Oh, my God! This is barbaric. I can't possibly do this,'" Dr. Babaian says. The desire for effective treatment eventually overcomes most men's initial aversion to injections, he says, "and they find it's not all that bad." 

The medicines cost from $5 to $15 per dose. Each treatment lasts from 30 minutes to an hour. One recent study found that in a group of 44 couples, injections were preferred over vacuum devices by a two-to-one margin, and the preference for injection was even greater among those with impotence caused by prostatectomy. 

While drug injections usually work, there are some side effects such as scarring, and priapism, a risk of painful, long-lasting erections. 

A variation of this therapy, called MUSE, requires insertion of a tablet suppository of prostaglandin E1 (Alprostadil) into the urethra at the tip of the penis. While one group of researchers reported two-thirds of the men in their study were able to maintain erections, with only a few cases of mild pain; another study found just the opposite: two-thirds of the men tested could not achieve sustained erections. And in daily practice, some doctors say that while inserting a tablet may sound more appealing than injections, relatively few of their prostate cancer patients get satisfactory results with MUSE. 

A variety of penile implants are available, but doctors point out that these are expensive, more than $5,000 for the device and another $15,000 for surgery and hospital fees. However, doctors say Medicare and most insurance plans do cover treatment for impotence caused by cancer therapies. The surgery itself is extensive and sophisticated. One doctor says that in his experience very few men who have just endured treatment for prostate cancer are interested in undertaking further surgery. Some implants are always semi-rigid, while others are inflatable. Experts say all penile implants carry a risk that the patient will eventually need yet another operation to repair or replace the prosthesis. 

Herbs or other non-prescription products are frequently touted as remedies for impotence, among the more popular are Saw Palmetto and Yohimbe. 

Clinical sexologist Joe Marzucco, of Kaiser Permanente in Portland, Ore., says he has had mixed results with a combination of Yohimbe and an anti-depressant drug. "Typically those medicines do not work in a man who's had a radical (prostatectomy), but will frequently work for men who have had radiation therapy," he says. 

Dr. Montague, at the Cleveland Clinic, takes a less positive stance. He says scientific studies have found Saw Palmetto to be no more effective than a placebo. He says in careful tests, where neither patient nor researcher knows who is getting the active ingredient and who is getting placebo (a "double-blind" test), Yohimbe also fails. "It's the most widely prescribed medication for this, but in good double-blind studies it does not appear to be effective." 

Experts point out that whatever course a man chooses he is more likely to be successful if his partner is involved throughout the process. Patients may need to be persistent, in order to make sure they are aware of all the information and treatment that is available. 

"Most people are being told what the options are, but [I] think there are still a fair number of people who aren't being told everything," Dr. Babaian says. 

Doctors say men need to keep it all in perspective. "That sex is enjoyable, that sex has been enjoyed for a long period of time in their relationship, and if they can just get away from the notion that sex is only intercourse," advises sexologist Marzucco, "then I think that dealing with and accommodating the problems they will encounter will be easier." 

David Schmidt says his personal experience with his partner supports that philosophy. "It's okay," he says, "it's not the end of the world. There are other ways of doing it." 

Dr. Montague wants every man with prostate cancer to know that fear of impotence is no reason to be reluctant about potentially life-saving therapy. "The treatment that we have today is good enough that if they have a problem --and sexual problems are not inevitable after prostate cancer treatment, but when they occur-- they can be treated." 


Sources: Cancer 1997 Feb 1;79(3):538-544; Erectile functioning of men treated for prostate carcinoma. Robinson JW, Dufour MS, Fung TS 

American Urological Association Treatment Guidelines For Impotence, Nov. 96 

Br J Urol 1997 Jun;79(6):952-957; Intracavernosal drug-induced erection therapy versus external vacuum devices in the treatment of erectile dysfunction. Soderdahl DW, Thrasher JB, Hansberry KL 

N Engl J Med 1997 Jan 2;336(1):1-7; Treatment of men with erectile dysfunction with transurethral alprostadil. Medicated Urethral System for Erection (MUSE) Study Group. Padma-Nathan H, Hellstrom WJ, Kaiser FE, Labasky RF, Lue TF, Nolten WE, Norwood PC, Peterson CA, Shabsigh R, Tam PY 

Urology 1997 Nov;50(5):809-811; MUSE therapy: preliminary clinical observations. Werthman P, Rajfer J 

Impotence. NIH Consens Statement 1992 Dec 7-9;10(4):1-31. 

Br J Urol 1996 Aug;78(2):257-261; Sildenafil, a novel effective oral therapy for male erectile dysfunction. Boolell M, Gepi-Attee S, Gingell JC, Allen MJ; Department of Urology, Southmead Hospital, Westbury on Trym, Bristol, UK. 


Source: Exclusive SHN Report 

Copyright 1998 by Sapient Health Network. All rights reserved. 

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