A clinical trial for testosterone gel in older, frail men was halted after only six months because some men in the study developed heart problems. According to a report in the New England Journal of Medicine, men using the testosterone gel were also more likely to suffer skin and breathing problems than those treated with a placebo.
The gel being studied is sold under the brand name Testim by Auxilium Pharmaceuticals. The halted clinical trial, which was conducted by Boston University, was designed to determine if men over 65 who already had mobility problems could benefit from use of the gel. Levels of testosterone decline with age, but it is already known that supplementing it in healthy men can build muscle mass and strength and lower the risk of disability.
Testosterone therapy is approved and has been shown to be effective in men with hypogonadism (low testosterone levels). While testosterone is currently not approved for the treatment of older men with mobility problems or frailty, such off-label use is not uncommon.
The 209 men in the Testim trial were all over 74 years old, and many suffered from obesity, diabetes, high blood pressure and high cholesterol. While the strength and mobility of the 106 subjects receiving Testim did improve, 23 in that group experienced a side effect such as fainting, chest pain or heart attack. One man in the testosterone group died of a suspected heart attack. Only five in the 103-man control group experienced similar problems.
The researchers halted the trial in December 2009.
“Testosterone gel … was associated with a greater frequency of adverse events, particularly cardiovascular, respiratory, and dermatologic events,” the authors wrote. “The divergence between the [testosterone gel and placebo gel] groups in the incidence of cardiovascular adverse events was maintained over the six-month intervention period and did not diminish during the three-month observation phase that followed the intervention period.”
The authors of the study noted that the testosterone doses used in this study were higher than often seen in doctors’ offices and other trials.
They also cautioned that “the lack of a consistent pattern in these events and the small number of overall events suggest the possibility that the differences detected between the two trial groups may have been due to chance alone.” Finally, they cited limitations in the study including the small number of participants and events, the methods used to ascertain some adverse events (some were self-reported)), and the fact that the study was limited to a very specific population and cannot be generalized to other groups.