Researchers at Vanderbilt University Medical Center report that the use of opioid analgesics by patients with rheumatoid arthritis may increase their likelihood of serious infection and subsequent hospitalization. Their study, “Opioid Analgesics and the Risk of Serious Infections Among Patients With Rheumatoid Arthritis: A Self-Controlled Case Series Study,” was published in the journal Arthritis & Rheumatology.
Patients with rheumatoid arthritis (RA) are at increased risk of serious infection. This elevated risk is thought to be associated with the autoimmune disease process itself, the impact of RA comorbidities, and the use of immunosuppressive medications, including glucocorticoids and disease-modifying antirheumatic drugs (DMARDs). Opioid analgesics are increasingly being prescribed for patients with chronic non-cancer pain, including those with RA , although the long-term safety of these medications remains unknown.
To determine whether opioid use is associated with an increased RA risk of serious infection, Andrew D. Wiese and colleagues identified a group of 1,790 RA patients from a cohort of 13,796 RA patients, and from information in the Tennessee Medicaid database.
Patients included in the analysis had at least one billing code for RA, and a prescription for either cyclophosphamide, D-penicillamine, gold salts, adalimumab, infliximab, cyclosporine, methotrexate, etanercept, hydroxychloroquine, leflunomide, minocycline, or sulfasalazine. Researchers evaluated the incidence of serious infection and opiate use among the self-controlled case series (SCCS) cohort.
The incidence rate of at least one use of opioids was 95% in the SCCS cohort, compared with 87.3% for the overall cohort. Use in the SCCS cohort included hydrocodone (48%), propoxyphene (22.3%), oxycodone (12.8%), morphine (5.7%), codeine (5%), and other opioids (6.2%).
The results revealed that among the 1,790 patients who had at least one hospitalization for serious infection, the adjusted incidence rate of serious infection was higher during periods of current opioid use compared to nonuse, with an incidence rate ratio (IRR) of 1.39.
Results also showed that the incidence rate was higher during periods of long-acting opioid use, immunosuppressive opioid use, and new opioid use compared to nonuse (IRR 2.01, IRR 1.72, and IRR 2.38, respectively).
In addition to associating opioid use with an increased risk of serious infections and hospitalizations, researchers found that the incidence rate of infections was higher in RA patients during periods of current opioid use, and in those using higher daily doses, long-acting formulations, and opioids with immunosuppressive properties.