Long-term use of prescription painkillers for back pain linked to erectile dysfunction in men

The researchers included more than 11,000 men with back pain in the study and examined their health records to find out if the men taking prescription painkillers were more likely to also receive prescriptions for testosterone replacement or ED medications.

More than 19 percent of men who took high-dose opioids for at least four months also received ED prescriptions, while fewer than 7 percent of men who did not take opioids received ED prescriptions.

In the study, men over 60 were much more likely to receive ED prescriptions, but even after researchers adjusted for age and other factors, men taking high-dose opioids were still 50 percent more likely to receive ED prescriptions than men who did not take prescription painkillers.

"Men who take opioid pain medications for an extended period of time have the highest risk of ED," said study lead author Richard A. Deyo, MD, MPH, investigator with the Kaiser Permanente Center for Health Research and professor of Evidence-based Family Medicine at Oregon Health & Science University.

"This doesn't mean that these medications cause ED, but the association is something patients and clinicians should be aware of when deciding if opioids should be used to treat back pain," Dr. Deyo added.

Opioid use is growing in the U.S. According to the Centers for Disease Control and Prevention's Mortality and Morbidity Report, prescription opioid sales quadrupled between 1999 and 2010. Another recent survey, published in the journal Pain, estimates 4.3 million adults in the U.S. use these opioid medications on a regular basis. The most commonly used prescription opioids are hydrocodone, oxycodone and morphine.

"There is no question that for some patients opioid use is appropriate, but there is also increasing evidence that long-term use can lead to addiction, fatal overdoses, sleep apnea, falls in the elderly, reduced hormone production, and now erectile dysfunction," says Dr. Deyo, who has spent more than 30 years studying treatments for back pain.

For this study, Dr. Deyo and colleagues identified 11,327 men in Oregon and Washington enrolled in the Kaiser Permanente health plan who visited their doctors for back pain during 2004. The researchers examined the men's pharmacy records for six months before and after the back-pain visit to find out if they had filled prescriptions for opioids and for ED medications ortestosterone replacement.

Opioid use was categorized as "none" for men who did not receive a prescription for opioids; "acute" for men who took opioids for three months or less; "episodic" for men who took opioids for more than three months, but less than four months and with fewer than 10 refills; and "long-term" for men who took opioids (a) for at least four months or (b) for more than three months with 10 or more refills. Anything more than 120 mg of morphine equivalent was categorized as high-dose use.

More than 19 percent of the men who took high-dose opioids for at least four months also received ED medications or testosterone replacement. More than 12 percent of men who took low-dose opioids (under 120 mg) for at least four months also received ED medications or testosterone replacement. Fewer than 7 percent of men who didn't take opioids received ED medications or testosterone replacement.

Researchers found that age was the factor most significantly associated with receiving ED prescriptions. Men 60 to 69 were 14 times more likely to receive prescriptions for ED medication than men 18 to 29.

Depression, other health conditions (besides back pain), and use of sedative hypnotics like benzodiazepines also increased the likelihood that men would receive ED prescriptions.

But even after researchers adjusted for these factors, long-term opioid use increased the likelihood of also receiving prescriptions for ED medication by 50 percent.