Published: Apr. 1, 2005
Updated: Aug. 11, 2005
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By Duke Medicine News and Communications
Many men use pharmaceutical testosterone to help with lowered sex drive, loss of energy and other symptoms associated with entering mid-life. An expert says a large-scale clinical trial is needed to learn whether these supplements are indeed safe and effective.
As men enter mid-life, they often start to experience decreased sex drive, diminished energy, memory problems and other symptoms of physical and mental change. This transitional phase, somewhat analogous to menopause in women, is popularly known as "manopause" or "viripause."
A growing number of men are turning to hormone replacement therapy, in the form of testosterone supplements, to help their bodies adjust to these changes.
Testosterone replacement therapy, which must be prescribed by a physician, is currently approved by the Food and Drug Administration for treatment of only one condition in men: hypogonadism. In this condition, a man's testicles and scrotum are reduced in size, resulting in abnormally low sperm production.
However, more and more men, middle-aged and older, are taking the medication to boost their sex drive, build muscle mass, strengthen bones and help restore youthful vigor.
While many advocates regard testosterone supplements as a pharmaceutical fountain of youth, Dr. Dan Blazer, a professor in the Department of Psychiatry and Behavioral Sciences at Duke University Medical Center, says men should be aware of potential health dangers.
"There are still no large studies that have looked at the health risks," says Blazer. "There is some suggestion that testosterone therapy may lead to an increase in prostatic hypertrophy and in the level of the hormone that is tested for in looking at the possibility of prostate cancer, prostatic-specific antigen or PSA."
Blazer was a member of a scientific task force group that recommended in 2003 that a large-scale clinical trial be undertaken to study the safety and effectiveness of testosterone therapy. Since that report, no such trial has taken place, though a number of smaller trials have been conducted.
"In an ideal world, what we would like to do is show the drug is effective in a particular area and then to study it in more detail, given the fact that it's been shown to be effective. Or else, get the evidence out there that this drug has not been shown in clinical trials to be effective and hopefully that would stop the enthusiasm for using the drug.
"That's of concern because it's very hard to pin down exactly what the drug may be doing. Most medications are effective in one or two areas and not in others and may often carry harmful effects."
Blazer says one reason for the drug's recent surge in popularity may be the availability of a new, improved treatment option.
"It's not a big deal yet, but it's getting to be a much bigger deal. The recent introduction of some newer ways to deliver the drug, specifically by means of a topical gel, has increased the use significantly. The gel works much better than some of the other methods that have been used in the past, such as a patch."
Despite the many claims for testosterone replacement therapy, Blazer believes caution is called for until there is conclusive evidence as to its efficacy and safety.
"We feel like we're at a very early stage of understanding what the therapeutic benefit of the testosterone might be, and we're also at a very early stage in understanding what the potentially harmful side effects may be."