Testosterone: Benefits, Risks Unknown
Experts Urge More Research of Testosterone Therapy
Dramatic Surge in Gel, Patch Prescriptions
An estimated 2 million prescriptions for testosterone therapy were written in 2002 for thousands and thousands of men -- a dramatic increase since the patch and gel were developed, Blazer said. Most were prescribed for middle-aged men.
His committee listened to prominent researchers and reviewed the available scientific literature on testosterone therapy. They identified only 31 trials involving older men. Most studies were quite small with fewer than 50 participants, and only one lasted longer than a year.
"We quickly determined that more clinical trials are needed ... and that the most immediate goal should be to establish whether testosterone therapy results in clear benefit for aging men," Blazer said.
The committee's recommendations:
- Small, short-term studies looking at immediate risks and benefits should be conducted -- whether strength, sexual function, mental function, and general well-being are improved. If those studies do not show benefits, "then a long-term study would not be warranted," Blazer said.
- The studies should involve only men age 65 and older, since that age group has the lowest testosterone levels and would therefore shed light on the benefits of this therapy, if any.
- Men with high risk of prostate cancer should be excluded from studies.
- Studies should also assess increased risk of prostate cancer.
Testosterone therapy should not be viewed as a preventive measure for age-related conditions, Blazer said. "To date, the evidence is almost nil -- virtually nonexistent.
"Until the efficacy and safety of testosterone therapy in older men is firmly established, we believe that its use is appropriate only for those conditions approved by the FDA and that it is inappropriate for wide-scale use to prevent possible future disease or to enhance strength or mood in otherwise healthy older men," Blazer said.
The committee said they found no evidence of major adverse effects from testosterone therapy, but they add that the evidence for its safety is lacking.
"There are alternative treatments for many of these [age-related] problems, some on the market, some being developed ... that may have lower risk than testosterone therapy," he said.