Monday, October 23, 2006

Impotence Common After Kidney Transplant

Sexual difficulties are among the 10 symptoms most frequently reported by men with kidney failure. These are caused by a combination of fatigue, hormonal changes, nerve damage and arterial disease. Of all the symptoms experienced before transplant, sexual difficulties are the only ones that don't improve afterwards.

A recent study in France reports that erectile dysfunction is surprisingly common in men who have had kidney transplants. Researchers gave a well-established questionnaire called the International Index of Erectile Function, or IIEF, to 271 men who had had kidney transplants and were sexually active. The men answered questions about five areas of their sexuality: erectile function, orgasm, sexual desire, satisfaction with intercourse, and overall satisfaction with their sex life. The researchers then compared this group of men with those that had been studied when the questionnaire was developed.

"A significant decrease in erectile function and intercourse satisfaction was observed in male kidney transplant recipients compared to the controls. The prevalence of erectile dysfunction after renal transplantation was surprisingly high," according to Dr. Lionel Rostag of Hospital Rangueil in Toulouse, France, and colleagues, in the May issue of Transplantation. "Erectile dysfunction affected approximately every other sexually active patient (55.7 percent)." They note that among the general population, impotence affects only about one in 10 men.

The two aspects of sexuality that differed significantly between the transplant patients and the control group were the ability to achieve and sustain an erection and overall satisfaction with intercourse. The groups did not differ on interest in sex, ability to achieve orgasm or overall satisfaction with their sex life.

"Orgasmic function and most interestingly, overall satisfaction scorings were not affected," noted the researchers. They noted that while interest in sex is usually impaired in patients with kidney failure, the transplants restore patients' hormonal balance and this problem usually disappears.

Previous research had found that sexual dysfunction in both male and female patients was the only symptom that didn't improve significantly after kidney transplant, explained the researchers. However, they did not expect to find that over half of the men in their study reported difficulties, especially since the average age of this group as a whole (age 48) was younger than the control group (average age 55).

In the current study, the factors most closely related to sexual dysfunction in the transplant recipients were age, the amount of time they'd spent on dialysis before their transplants, and whether they'd had more than one transplant. Men who reported sexual difficulties were significantly older than those who didn't and had spent an average of almost eight years on dialysis -- compared to six years for those without difficulties. Twenty-one percent of those with sexual problems had had more than one transplant compared to just eight percent of those without problems.

Several factors could contribute to the sexual difficulties experienced by these men, Rostag and colleagues explained. In particular, kidney failure and dialysis both damage the blood vessels that lead to the penis as well as the tissues of the penis itself. The best way to avoid this damage, they concluded, is to do kidney transplants as soon as possible and reduce the amount of time on dialysis.

"Swift access to transplantation is widely recommended because it is more effective and less costly than dialysis," the researchers stated. "Another reason should be to preserve an intimate but very significant aspect of quality of life, i.e., sexuality."

In addition, specialists who work with kidney transplant patients should be aware of potential problems, evaluate them and be ready to help treat them, concluded the researchers.

"In view of the recent development of effective oral therapies for erectile dysfunction, nephrologists [kidney specialists] and transplant surgeons alike should be aware of the magnitude of patients' unexpressed expectations and of the means available for male patients to disclose these. In this respect, [the IIEF] could be used routinely for diagnosis and treatment evaluation."

Study Suggests Viagra Safe for Men Not Taking Nitrates

Taking a single dose of the popular impotence drug Viagra (sildenafil) caused no cardiovascular problems in 14 men who had severely clogged arteries, researchers report in the June 1, 2000, New England Journal of Medicine. Instead, Viagra decreased blood pressure slightly and boosted blood flow in coronary arteries, which is good for the heart.

"Viagra should be safe for many cardiovascular patients who are not on nitrates and who are capable of moderate activity," Dr. Howard C. Herrmann of the University of Pennsylvania in Philadelphia told HeartInfo/Mediconsult. Patients may want a stress test to make sure their heart can handle the exertion of intercourse, he said. Nitrates, a common heart medication taken for chest pain, are dangerous if used in combination with Viagra, studies have shown.

During the past couple of years, the Food and Drug Administration has raised concerns about Viagra by reporting that a significant number of men had heart attacks and cardiac arrests soon after taking the drug and before having intercourse. Researchers wondered if this was because many impotent men also have heart disease or if Viagra was dangerous to the heart.

Viagra works by inhibiting a type of enzyme in the penis, and similar enzymes are also found in the heart muscle. Researchers wondered if inhibiting the enzyme posed a cardiac risk, Dr. Herrmann explained.

As part of the open-label, non-blinded study, he and his colleagues gave 100 milligrams of the drug to 14 heart patients and then monitored their lung and heart function. All were
in their 50s and 60s and had at least one artery that was more than 70 percent blocked.

The men were on a variety of medications, but none were on nitrates. Almost half of the group had hypertension or diabetes, or were smokers. Before and 45 minutes after taking Viagra, the participants had their blood pressure, heart rate, and blood flow measured. The men did not have intercourse during the study, so it was not a test of the effects of Viagra on the heart during exertion.

On most measures of blood pressure and blood flow, Viagra did not appear to have any significant effect, the researchers report, "and it had no effect on pulmonary-capillary wedge pressure, right atrial pressure, heart rate, or cardiac output." There were no adverse effects on coronary blood flow. And none of the men in the study experienced any serious side effects, like low blood pressure or chest pain, that could be linked to Viagra, according to the authors.

"Our data support the consensus position of the American College of Cardiology and the American Heart Association that sildenafil is safe for patients with stable coronary artery disease who are not taking medications containing nitrates," the authors conclude.

Pfizer Inc, which makes Viagra, funded the study.

The American College of Cardiology and the American Heart Association recommend that patients with stable coronary disease who are not taking nitrates should consult their physician about the risks and benefits of taking Viagra. Those taking a combination of blood pressure-lowering drugs may be at increased risk for drug interactions, they note.

In addition, Dr. Andrew P. Levy, Medical Advisor for HeartInfo, cautions that "It is difficult to make many conclusions from such a small study. Men with heart disease should consult their doctor before taking Viagra. We don't yet understand why the drug may cause death, and this study is not definitive."

Erectile dysfunction affects up to 30 million men in the United States, and shares certain risk factors with heart disease, including age, diabetes, hypertension, hypercholesterolemia, and smoking.