FDA Adds Warning to Testosterone Products About Potential for Blood Clots
Agency sees risk of VTE
The FDA is requiring manufacturers to include a general warning in the drug labeling of all approved testosterone products about the risk of venous thromboembolism (VTE), which includes deep-vein thrombosis (DVT) and pulmonary embolism (PE).
The risk of VTE is already included in the labeling of testosterone products as a possible consequence of polycythemia, which sometimes occurs with testosterone treatment. Because there have been postmarketing reports of venous blood clots unrelated to polycythemia, the FDA is requiring a change to the labeling of all testosterone products to provide a more general warning regarding VTE and to ensure that this risk is described consistently in the labeling of all approved testosterone products.
Because these clots occur in the veins, the new warning is not related to the FDA’s ongoing evaluation of the possible risk of stroke, heart attack, and death in patients taking testosterone products. The agency is currently evaluating the potential risk for these cardiovascular events, which are related to blood clots in the arteries and were described in a drug safety communication posted in January 2014.
In that communication, the FDA announced that it had decided to reassess the risk of stroke, heart attack, and death in men taking FDA-approved testosterone products based on two separate studies.
The first study was an observational investigation in older men in the U.S. Veterans Affairs health system, published in JAMA in November 2013. The men included in this study had low serum testosterone and were undergoing coronary angiography to assess for coronary artery disease. Some of the men received testosterone treatment, while others did not. On average, the men who entered the study were about 60 years old, and many had underlying cardiovascular disease. This study showed a 30% increased risk of stroke, heart attack, and death in the group that had been prescribed testosterone therapy.
A second observational study reported an increased risk of heart attack in older men, as well as in younger men with pre-existing heart disease, who filled a prescription for testosterone therapy. The study reported a two-fold increase in the risk of heart attack among men aged 65 years and older in the first 90 days following the first prescription. Among younger men less than 65 years old with a pre-existing history of heart disease, the study reported a two- to three-fold increased risk of heart attack in the first 90 days after a first prescription. Younger men without a history of heart disease who filled a prescription for testosterone, however, did not have an increased risk of heart attack.
Testosterone products are FDA-approved for use in men who lack or have low testosterone levels in conjunction with associated medical conditions. Such conditions can include the failure of the testicles to produce testosterone because of genetic problems, chemotherapy, or other reasons.