Rheumatoid Arthritis Drug Linked to Increased Likelihood of Shingles

A drug designed to treat patients with rheumatoid arthritis could also make them more susceptible to shingles, according to the results of a recent study.

In study results published in Arthritis & Rheumatology, the authors looked at the likelihood of patients taking tofacitinib, an oral JAK inhibitor, also being diagnosed with herpes zoster (HZ), including shingles. The study involved looking at phase II and III trials for the drug and the incidence rates of herpes zoster per 100 patient years. The report noted that there was a 95% confidence interval “calculated by exposure group.”

Out of 4789 patients studied during the review 239 were shown to have tofacitinib-associated herpes zoster. An overwhelming majority of those cases (a total of 208) were women with an average age of 57. The age range for female participants was between 21 and 75 according to the authors.

“One HZ case (0.4% was multidermatomal; none of the cases involved visceral dissemination or death,” they said. From the group of those developing HZ, 24 patients opted to permanently stop taking the drug, and 16 were either hospitalized or given intravenous drugs as a result.

“The crude HZ IR across the development was 4.4 per 100 patient-years (95%CI 3.4-4.9),” the authors noted. That ratio was much higher in Asia, which was recorded as 7.7 per 100 patient-years (95% CI 6.4-9.3). Another factor studied was older age (odds ratio 1.9, 95%CI 1.5-2.6).

Results from the study were also similar for those patients who were prescribed 5 mg twice daily (4.4 per 100 patient-years, 95%CI 3.2-6.0), and patients prescribed 10 mg twice daily (4.2 per 100 patient-years, 95% CI 3.1-5.8). In the placebo group, the authors noted an incidence rate of just 1.5 per 100 patient-years (95% CI 0.5-4.6).

Looking at the wider picture the authors said the data is important as more than one-third of all Americans will develop shingles in their lifetime and almost all adults in the country over the age of 40 have been exposed to it in their lifetimes. Developing shingles, studies have shown, can lead to patients developing postherpetic neuralgia in approximately 15% of cases which can cause long-term disability.