Feb. 17, 2009 -- Some of the powerful new drugs that offer relief to rheumatoid arthritis sufferers may increase risk of a different kind of suffering: shingles.
Humira, Kineret, and Remicade are all biologic agents called monoclonal antibodies. Each of these drugs increased shingles risk by about 80%. Enbrel, a slightly different kind of TNF-alpha blocker, did not, says Anja Strangfeld, MD, of the German Rheumatism Research Center in Berlin.
"We compared these different types of TNF inhibitor with conventional disease-modifying anti-rheumatic drugs and we found there is an increased risk of herpes zoster in patients treated with the monoclonal antibodies," Strangfeld tells WebMD. The risk from Enbrel was not significant.
The TNF-alpha blockers have made dramatic improvements in the lives of people with rheumatoid arthritis. The drugs are also helpful in ankylosing spondylitis, psoriatic arthritis, and Crohn's disease because they calm the out-of-control immune responses at the root of these diseases.
But the new findings strongly suggest that some patients taking Humira, Kineret, and Remicade will have shingles attacks, especially those who have already had shingles, says Richard J. Whitley, MD, professor of pediatrics, microbiology, medicine, and neurosurgery at the University of Alabama, Birmingham.
"It's pretty clear that if you have had previous zoster and take these anti-TNF monoclonal antibodies, you are going to reactivate it," Whitley tells WebMD. "I think it is reasonable to go with Enbrel for patients with prior zoster."
Although there's strong evidence that these anti-TNF-alpha agents increase the risk of shingles, it's not clear whether they increase the risk of severe shingles.
On one hand, about one in five of the German arthritis patients who developed shingles suffered complications. That's higher than one would expect in 50-something men, notes infectious disease expert Robert F. Betts, MD, professor of medicine at the University of Rochester, N.Y.
On the other hand, Whitley notes, there were relatively few cases of postherpetic neuralgia, the dreaded shingles side effect of lasting pain.
But Strangfeld and Betts suggest that patients planning to start anti-TNF treatment postpone the start of therapy for the few weeks it takes for the shingles vaccine to take effect. Whitley, too, thinks this is a good idea, but like his colleagues, he'd like to see a clinical trial prove that it works safely before recommending it to patients.
Betts notes that an inactivated version of the shingles vaccine is in the works. In early studies, this vaccine appears safe for use in people with weakened immune systems.
The Strangfeld study, and Whitley's editorial commentary, appear in the Feb. 18 issue of the Journal of the American Medical Association.
(What does shingles look like? See WebMD's shingles slideshow.)