Back pain study questions Enbrel's effectiveness for relief


(CBS News) Millions of Americans suffer from back pain and are desperate for relief. While new genetically engineered drugs show great promise, a new study found the tried and true method of steroid injections was more effective to the newer, safer compounds at easing back pain.

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For the study, researchers from Johns Hopkins University in Baltimore tested back pain treatments on 84 adults with sciatica. Sciatica is back pain that's typically caused by a herniated disk that radiates to the hip, outer side of the thigh and/or leg, due to pressure on a nerve.

The researchers randomized study participants to either receive either an epidural injection of 60 milligrams of an anti-inflammatory steroid, 4 milligrams of another type of anti-inflammatory drug named etanercept, or a placebo. Sold under the brand-name Enbrel, etanercept is a so-called "tumor necrosis factor (TNF) inhibitor" that's genetically engineered to target the inflammatory molecules that cause sciatica and other pain conditions (like arthritis), and keep the molecules from binding to receptors in the nervous system, thus preventing pain. Steroids work by combating inflammation generally.

One month after receiving the second of two injections, the researchers tested the patients and found those taking steroid reported less pain and disability compared to participants in the other two groups. Seventy-five percent of patients taking epidural steroids reported a 50 percent or greater reduction in pain after one month compared with 50 percent of saline patients and 42 percent of etanercept patients. Twenty-one percent of patients taking steroids reported low levels of disability, compared with 38 percent of patients taking etanercept.

The study is published in the April 17 issue of the Annals of Internal Medicine.

Researchers called the findings disappointing, since drugs like etanercept were created to find a safer and reliable alternative to steroids for pain, as steroids may lead to side effects and complications and only relieve pain temporarily.

"People are desperate for a safer, more effective drug," study author Dr. Steven P. Cohen, an associate professor of anesthesiology and critical care at Johns Hopkins University School of Medicine, said in a written statement. "This new treatment shows a lot of promise, but at least in the doses we gave it -- the dose known to be safe -- steroids still work better. And in those lower doses, etanercept may not be the drug everyone's hoping it is. There's still a lot more work to be done."

Steroids weren't a miracle drug either. After six months, Cohen said, slightly more patients in the saline and etanercept groups reported less pain than those taking steroids.

"The effect of the steroids didn't last," Cohen said, "affirming the fact that steroids work, but not for very long." He said future research should look at if higher doses of etanercept could be safe for patients.

Dr. Daryll Dykes, spokesman for the American Academy of Orthopedic Surgeons, who was not involved in the research, told USA Today that many people with back pain "do heal on their own without treatment. But for the people who suffer from this kind of pain, and it can be intense, it is important to know studies are looking at different options."

Dr. Roger Chou, an associate professor of general internal medicine at Oregon Health and Science University in Portland, emphasized to HealthDay that the benefits seen from steroids were only short term.

"These benefits do not appear to last and they have a good chance of improving without the injection," Chou said. "I think a lot of doctors (and patients) think that epidural steroid injections are much more effective (and longer lasting) than the evidence shows that they really are."

Cohen said in the end, more sciatica treatments are needed, but one regimen that already exists might help.

Cohen told Reuters besides the treatments that have the strongest evidence behind it are exercise programs and losing weight for people who are too heavy.

Said Cohen, "People have to have realistic expectations."

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