About a year ago, a major retrospective study showed that men prescribed erectile dysfunction (ED) drugs, such as sildenafil (Viagra) had markedly higher rates of sexually transmitted diseases. This relationship, however, could have more to do with behavior than with ED drug use.
Anupam Jena, MD, PhD, of Massachusetts General Hospital in Boston and colleagues analyzed insurance claims for 1.4 million men ages 40 and older (mean age 61) and found that users of prescription ED drugs developed STDs at a rate of 214.9 per 100,000, with HIV cases accounting for 70 percent of the total, compared with 106 per 100,000 among men not using these drugs.
Data for the retrospective cohort study came from pharmacy claims in 44 large employers’ health plans from 1997 to 2006. About 34,000 men ages 40 and older in the database had received at least one prescription for an ED drug, and 1.38 million had not.
Users had higher rates of several comorbidities including cancer, depression, diabetes, high cholesterol, and hypertension by about 50% in each case.
The data, however, showed that STD rates among the ED drug users were higher than in nonusers even before the men received their first prescription, suggesting that it was the users’ behavior, not the drugs, which was the responsible for the relationship. The authors reported these findings in the Annals of Internal Medicine.
The authors believe that the “use of ED drugs by middle-aged and older patients may serve as a simple screening tool for physicians to use in identifying those patients who may benefit from reminders about safe sexual practice.”
The reported that HIV/AIDS rates in people older than 50 years in 2005 were higher than for people in their 20s, and these rates have increased in older people while rates among other age groups have decreased.
According to CDC statistics, other STDs are less common in people over 40 compared with younger individuals, with little change in the rates from 2004 to 2008.
Jena and colleagues found little difference when they examined quarterly STD diagnosis rates in the year before the first prescription for ED drugs versus the following year.
Some limitations for this study were no data on frequency of sexual encounters, practices, or number or gender of partners; potentially inaccurate or incomplete data on ED drug use; probable underestimates of actual STD incidence, due to nondiadnosis or care outside of the health plan; and complex “sexual network effects” and uncertain risks per encounter.