By: Jenny Park PharmD Candidate c/o 2015
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Testosterone is a hormone essential to male development. However, treatment of testosterone deficiency is FDA approved only when accompanied with another medical condition such as failure of testicles to produce testosterone due to chemotherapy or even genetic conditions.1 In 2011, 5.3 million prescriptions for testosterone were written in the United States. Treatments for low testosterone are now at an estimated $2 billion a year in the U.S. Up to 25% of testosterone prescriptions are written without the healthcare provider checking a man’s testosterone level.2 Testosterone therapy is prescribed to men in order to increase hormone levels and improve sex drive, bone density, and muscle mass. However, the benefits and risks of long-term testosterone therapy are not well known. Testosterone therapy may be associated with a higher risk of heart attack, stroke, and death.3 The FDA has launched an investigation to weigh the benefits against the risks after two large new studies—“Association of Testosterone Therapy With Mortality, Myocardial Infarction, and Stroke in Men With Low Testosterone Levels” and “Plos One Study”—linked prescription testosterone therapy to an increased risk for cardiovascular events.4
The FDA was prompted to reassess the cardiovascular safety of testosterone therapy by an observational study of U.S. Veterans published in the Journal of the American Medical Association (JAMA) in November 2013.1,4 The men included in this study had low serum testosterone (<300 ng/dL) and underwent coronary angiography (imaging of the blood vessels of the heart) in the Veterans Affairs (VA) system between 2005 and 2011. The subjects of the study were a mix of people who received testosterone treatment and those who did not. The study published in JAMA reported a 30% rise in the risk for stroke, heart attack (MI) and death in men 60 or older who were prescribed testosterone. Of the 7,486 patients who did not receive testosterone therapy, 681 died, 420 had MIs, and 486 had strokes. Among 1,223 patients receiving testosterone therapy, 67 died, 23 had MIs, and 33 had strokes.4Prima facie, it appears as if the group receiving testosterone had fewer adverse consequences, but these numbers are confounded by the fact that the men who received testosterone were more likely to be younger and to have fewer comorbidities than those who did not receive testosterone. Therefore, after considering the inherently increased risk of adverse outcomes for older patients and those with comorbidities, it was concluded that testosterone therapy increased the risk of adverse outcomes among the men in the VA health care system. 4
In the PLOS ONE study, the researchers compared rates of heart attacks in 55,593 middle-aged and older men in the 90 days after they received a new testosterone prescription with rates during the year prior to the initial prescription. Also, pre- and post-prescription heart attack rates were compared to a control group of 167,279 men who were treated for erectile dysfunction with sildenafil (Viagra®) and tadalafil (Cialis®). It was found that men who received testosterone therapy, the risk for non-fatal heart attack jumped by 36% in the 90 days after starting the use of testosterone. Among men age 65 an older, rate of heart attack soared by 219% in 90 days among those who received testosterone therapy, whether or not they had a history of heart disease. In men under 65, those with a prior history of heart disease had nearly tripled the 90-day heart attack risk. Regardless of these cardiovascular related events, physicians should always talk about the risks and benefits and long term effects of taking any hormonal therapy in order to better educate their patients.
SOURCES:
- FDA. Safety Announcement. FDA website. Available at <http://www.fda.gov/Drugs/DrugSafety/ucm383904.htm> Accessed April 8 , 2014
- Rabin R. Weighing Testosterone’s Benefits and Risks. NY Tines Website. Available at < http://well.blogs.nytimes.com/2014/02/03/weighing-testosterone-benefits-and-risks/?_php=true&_type=blogs&_r=0> Accessed April 8, 2014
- Vigen R, O’donnell CI, Barón AE, et al. Association of testosterone therapy with mortality, myocardial infarction, and stroke in men with low testosterone levels. JAMA. 2013;310(17):1829-36.
- CBC. Testosterone therapy linked with heart risks in men. CBC website. Available at <http://www.cbc.ca/news/health/testosterone-therapy-linked-with-heart-risks-in-men-1.2415960> Accessed April 8, 2014.
[pubmed_related keyword1=”testosterone” keyword2=”men” keyword3=”adverse”]
