By Toni Clarke
WASHINGTON Jan 31 The U.S. Food and Drug
Administration said on Friday it is investigating the risk of
stroke, heart attack and death in men taking prescription
The move is based on the recent publication of two studies
that suggest an increased risk of heart attacks in men who take
testosterone, a hormone produced in the testicles that is
responsible for maintaining muscle bulk, bone growth and sexual
function, the FDA said.
Symptoms of low testosterone, or "Low T" as it is sometimes
called in advertisements, can include loss of libido,
depression, decreased muscle mass and fatigue.
The FDA said it has not concluded that testosterone
increases the risk of cardiac events but said it is issuing an
alert "while we continue to evaluate the information from these
studies and other available data."
The FDA's action comes two days after the publication of a
new study in the journal PLOS ONE, showing that men over the age
of 65 had a two-fold increase in the risk of heart attack within
90 days of filling an initial prescription for a testosterone
Among younger men under the age of 65 with a history of
heart disease, there was a two- to three-fold increased risk of
heart attack, though there was no increased risk in younger men
without a history of heart disease. In older men the increased
risk was seen whether or not they had a previous heart disease
The study, which analyzed 55,593 patients in a large
health-care database, echoed the results of a much smaller study
published in November in the Journal of the American Medical
Association which found that older men, many with underlying
heart disease, had a 30 percent increased chance of death, heart
attack and stroke after taking testosterone therapy.
The market for testosterone treatments currently include
skin patches, short-acting injections and topical gels. AbbVie
Inc's AndroGel, a treatment for hypogonadism and the
market leader, generated sales in 2012 of $1.2 billion. The
company did not immediately respond to a request for comment.
Testosterone therapy is only approved by the FDA for men who
lack or have low testosterone in conjunction with an associated
medical condition, such as a genetic failure of the testicles to
produce testosterone, or as a result of chemotherapy.
"Health care professionals should consider whether the
benefits of FDA-approved testosterone treatment is likely to
exceed the potential risks of treatment," the agency said in its
The FDA's move comes as it prepares to decide whether to
approve a long-acting testosterone product made by Endo Health
Solutions Inc. An advisory panel to the FDA split 9-9
at a meeting last year on whether the drug could safely be
prescribed for men with low testosterone.
Some panel members said the drug, Aveed, offers a valuable
alternative to existing products, especially since it is already
sold under the brand name Nebido outside the United States.
Others were unconvinced of the drug's safety.
Aveed has twice before been rejected by the FDA based on
concerns about injection-site reactions and the risk that it
could cause blockages in blood vessels in the lungs.
Dr. Sidney Wolfe, senior adviser to the consumer watchdog
Public Citizen, said in an interview that he thinks the FDA
should delay its decision on Aveed until the cardiac risks have
been assessed. He also said testosterone drugs should carry
cardiac risk warnings.