By Serena Gordon
MONDAY, Feb. 12, 2018 (HealthDay News) -- The bad news on opioids just keeps coming.
Not only are these painkillers implicated in millions of cases of addiction and tens of thousands of overdose deaths in the United States, new research now suggests that taking opioids can increase your risk of getting a pneumococcal infection by about 60 percent.
"The risk was increased even more for long-acting formulations, high-potency opioids and high doses of opioids," said the study's lead author, Andrew Wiese. He's a post-doctoral research fellow in the health policy department at Vanderbilt University School of Medicine in Nashville.
Pneumococcal infections are illnesses due to Streptococcus pneumoniae bacteria. They include ear infections, sinus infections, bacteremia (a bloodstream infection) and meningitis (infection of the lining of the brain), according to the U.S. Centers for Disease Control and Prevention.
The death rate is as high as 7 percent for pneumococcal pneumonia, 20 percent for bacteremia and 22 percent for meningitis, the researchers said.
The current study gathered data from the Tennessee Medicaid database. That means the study included data only from people taking legally available opioids.
The database included more than 1,200 people aged 5 years and older who had a pneumococcal infection. The researchers compared these people to more than 24,000 people who were matched by age, diagnosis date and county of residence.
The study can't prove a cause-and-effect relationship. However, Wiese said the findings -- combined with those from other studies and animal research -- suggest that there's a causal link. The existing research is enough to suggest caution in prescribing opioids, especially for those at high risk for infection, such as older people, he said.
Dr. Sascha Dublin described the study findings as "very important information for physicians." She's an associate scientific investigator at the Kaiser Permanente Washington Health Research Institute in Seattle. She also co-wrote an editorial published along with the study.
"People think of the risks of overdose or addiction with opioids, but I don't think infection risk is on most physicians' radar," Dublin said.
Still, a lot of questions remain, she noted. Why may opioids increase the risk of infection? And, is it all opioids or only some formulations? Some research has suggested that certain opioids, such as tramadol, may actually stimulate the immune system.
Wiese said that opioids are known to cause respiratory depression, which is a slowing of breathing. The drugs also have been linked to a higher risk for aspiration -- which is when a foreign substance, such as food, enters the lungs during breathing.
While these factors may play a role, Wiese said the risk for infection was similar in people with pneumonia and with non-pneumonia infections.
In addition, animal studies have shown that opioids can inhibit and disrupt the immune system, Wiese pointed out.
Dublin said, "We have all of this wonderful evidence from animal models pointing to the immune system as the cause, but we have to see if it holds true in people."
So, does this added risk mean that people should forgo pain-relieving medication to avoid the chance of infections?
No, Dublin said.
"There's a fair bit of confusion or myth that opioids are the gold standard for pain. Sometimes physicians feel they need to give an opioid, but in many cases, it's appropriate to try safer things first," she said.
"The safest choice for most people is acetaminophen [Tylenol]," Dublin said. "If that doesn't work, then ibuprofen. We also need to make sure patients have access to other possibilities, like physical therapy, massage or acupuncture for pain."
Wiese noted that "the primary audience for our study is providers who prescribe opioids."
So, he added, "What we're asking is that anytime a provider is prescribing an opioid, that they consider infection risk, especially for someone who might already have an infection or be at risk of an infection."
The study was published in the Feb. 13 online edition of Annals of Internal Medicine.