January 21, 2015
Common Treatments for Osteoarthritis Pain Are Not
Most Effective

Boston—Although they often are prescribed, oral nonsteroidal anti-inflammatory drugs (NSAIDs) are less effective for knee osteoarthritis (OA) pain than injections, according to a new review that also found OTC acetaminophen didn’t provide much relief either.

The systematic evidence review, published recently in the Annals of Internal Medicine, found that a variety of oral and injectable treatments for OA are more effective than placebo, but head-to-head comparisons are limited.

For the review of treatments for OA, which affects nearly 40% of Americans older than 45, the Tufts University–led researchers reviewed published research to compare the relative effectiveness of commonly used treatments. Selected were 137 randomized trials involving more than 33,000 participants that compared two or more of the following: acetaminophen, diclofenac, ibuprofen, naproxen, celecoxib, corticosteroid injections, hyaluronic acid injections, oral placebo, and placebo injections.

After 3 months, all interventions were found to be significantly better than oral placebo for improving OA pain. Acetaminophen, the most commonly used OTC treatment for knee OA, was shown to be the least effective option for pain, however. In fact, except for celecoxib, all treatments were significantly better than acetaminophen.

“For pain, all interventions significantly outperformed oral placebo, with effect sizes from 0.63 (95% credible interval [CrI], 0.39 to 0.88) for the most efficacious treatment (hyaluronic acid) to 0.18 (CrI, 0.04 to 0.33) for the least efficacious treatment (acetaminophen),” the authors write. “For function, all interventions except [intra-articular] corticosteroids were significantly superior to oral placebo. For stiffness, most of the treatments did not significantly differ from one another.”

Overall, injections were found to be the most effective treatment for knee OA pain. Even placebo injections were better than oral NSAIDs, the authors note, suggesting a placebo effect of the delivery method.

“This method allowed comparison of common treatments of knee OA according to their relative efficacy. Intra-articular treatments were superior to nonsteroidal anti-inflammatory drugs, possibly because of the integrated IA placebo effect. Small but robust differences were observed between active treatments,” the study concludes. “All treatments except acetaminophen showed clinically significant improvement from baseline pain. This information, along with the safety profiles and relative costs of included treatments, will be helpful for individualized patient care decisions.”

An accompanying editorial suggests that innovative research models will be essential to optimize pain control for patients with knee osteoarthritis.

U.S. Pharmacist Social Connect