In order to assess the safety and effectiveness of acetaminophen, previous studies have compared it to placebo and also to various NSAIDs (ibuprofen, diclofenac, arthrotec, celecoxib, naproxen). Researchers searched various databases and reviewed the published, randomized, controlled trials that compared acetaminophen to placebo or NSAIDs.
In their review, researchers assessed 15 randomized, controlled trials involving 5,986 study participants with hip osteoarthritis or knee osteoarthritis. The study participants took 4000 mg acetaminophen daily, placebo, or NSAIDS for about 6 weeks.
Acetaminophen Compared to PlaceboPeople who took acetaminophen had less pain while moving, resting, sleeping, and overall less pain compared to those taking placebo. Physical function and stiffness remained the same for the two groups. Pain decreased by 4 more points for people taking acetaminophen instead of placebo on a scale of 0-100.
Acetaminophen Compared to NSAIDsPeople who took NSAIDs had less pain and stiffness, and better physical function than those who took acetaminophen. Pain decreased by 6 more points for people who took NSAIDs rather than acetaminophen on a scale of 0-100.
Safety ComparisonSafety information revealed similarities between acetaminophen and NSAIDs, but study participants taking traditional NSAIDs did have more stomach problems (stomach pain, diarrhea, heartburn, nausea).
Points to RememberIn patients with osteoarthritis of the hip or knee:
- Acetaminophen relieved pain more than no treatment at all.
- NSAIDs improved pain, function, and stiffness more than acetaminophen, especially for those with moderate to severe pain.
The benefits between the drugs were considered modest. When choosing one drug over another, you should consider your own preference, cost, risks, drug availability, and of course -- your doctor's recommendation.
Source:
Acetaminophen for Osteoarthritis. Towheed et al. Cochrane Database of Systematic Reviews 2008 Issue 1.
http://www.mrw.interscience.wiley.com/cochrane/clsysrev/articles/CD004257/frame.html

