AHRQ issues two guides on osteoarthritis

March 5, 2007

The Agency for Healthcare Research & Quality (AHRQ) recently released guides for clinicians and consumers on the use of analgesics for treating pain associated with osteoarthritis (OA). The guides draw on a report, called "Comparative Effectiveness and Safety of Analgesics for Osteoarthritis," based on a review of 351 published research studies. It represents the most comprehensive analysis to date of analgesics for osteoarthritis pain.

The guides are the first ancillary products of AHRQ's Effective Health Care Program. The clinicians' guide summarizes the evidence on both Rx and OTC drugs, including information on the efficacy, cost, and potential adverse effects of non-steroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 (COX-2) inhibitors, acetaminophen, and others. The clinician guide also evaluates the scientific evidence applicable to the benefits and risks of these drugs.

"I thought the guides were quite good," said Steven Chen, Pharm.D., an associate professor of clinical pharmacy at the University of Southern California, Los Angeles. "We have needed these for a long time." He went on to say, "There is only one omission I might mention, and that involves the concomitant use of aspirin to reduce myocardial infarction [MI] risk." Chen said aspirin has, or appears to have, an interaction particularly with high does of ibuprofen. "It is enough of a concern that the Food & Drug Administration put out a bulletin in September (http:// http://www.fda.gov/cder/drug/infopage/ibuprofen/science_paper.htm) warning clinicians that this could be a problem." Circumstantial evidence suggests that 400 mg of ibuprofen attenuates the antiplatelet effect of low-dose aspirin when the drugs are dosed concomitantly. However, he said, the medication algorithm that is recommended in the AHRQ guides is appropriate.

Schuna is also concerned about the advice that patients should use medications such as naproxen or ibuprofen to reduce swelling or inflammation. Although most patients will understand what swelling is, he said, they may not understand what inflammation is. If they have swelling and inflammation, they should be referred to a physician, he advised. "In rheumatology, we are putting major emphasis on getting early treatment. Patients may delay treatment based on the advice given in this guide." The reason this may be an issue, he said, is that patients with OA can develop another type of arthritis on top of OA.

The original report, written by a team of experts at AHRQ's Evidence-based Practice Center at Oregon Health & Science University in Portland, is available on-line at http://effectivehealthcare.ahrq.gov/synthesize/reports/final.cfm. The researchers compared the analgesics' effectiveness and health risks, including MI and gastrointestinal (GI) side effects. They also recommended topics for further research. The investigators concluded that: