Use of opioid analgesics is associated with an increased risk of hospitalization for serious infections among patients with rheumatoid arthritis, according to a Vanderbilt study published in Arthritis & Rheumatology.
Previous animal and in vitro studies have established that certain opioids can lead to suppression of the immune system, but few studies have examined clinical implications of those observations.
Mr. Andrew Wiese, and colleagues compared the rate of serious infections during periods of opioid use to periods of non-use among 1,790 patients with rheumatoid arthritis enrolled in Tennessee Medicaid. Patients with rheumatoid arthritis are at high risk for serious infections and frequently use opioid analgesics to help manage their pain.
After accounting for potential confounding factors, “We found that periods of opioid use were associated with an almost 40 percent increase in the rate of serious infections compared to periods of no opioid use,” said Mr. Wiese, a doctoral student in Epidemiology.
The infections tracked in the study included pneumonia, meningitis, encephalitis, septicemia and several other serious infections.
“We also found that the highest rates of infection were associated with the use of high doses of opioids, long-acting opioids, and potentially immunosuppressive opioids identified from previous studies. These findings are consistent with the hypothesis that opioid use could affect the immune system and make individuals more susceptible to serious infections,” Wiese said.
Many different opioid formulations are clinically available, and investigators believe that only certain formulations have the ability to facilitate infections.
“Future studies will examine the association between specific opioids and the risk of infections. Identifying opioid formulations that are particularly problematic would be important to inform the selection of pain control medications, especially for vulnerable populations,” said Dr. Carlos Grijalva, associate professor of Health Policy and one of the co-authors of the study.
The study was funded by the National Institutes of Health (AG042981, AG043471, AR056116).