Research Activities, October 2013
Deciding which analgesic to use for older adults with osteoarthritis is a matter of comparing risks
Research on treatment of older adults for osteoarthritis (OA) pain finds that each of the main types of painkillers (acetaminophen, nonsteroidal anti-inflammatory drugs [NSAIDS], and opioids) has its use—but also has drug-specific concerns, according to a new systematic review.
OA is the most common joint disorder in the United States, and the leading cause of disability in patients 65 years or older. From the published findings of more than a decade of research studies, the researchers point out the pros and cons in older adults for each category of painkiller. Acetaminophen is recommended by practice guidelines as the first-line drug to treat mild to moderate pain associated with osteoarthritis of the knee or hip in older adults. However, concern has been raised by clinicians about the potential danger of acetaminophen-related liver toxicity.
In response, the U.S. Food and Drug Administration commissioned a working group and has required expanded warnings on nonprescription acetaminophen product boxes. However, the systematic review finds that data to support increased risk of liver toxicity in healthy older adults is sparse, but may be higher in the frail elderly. Based on the studies reviewed, the authors recommend limiting acetaminophen treatment to less than 4 g/day. When acetaminophen is not enough to control OA pain, NSAIDs are commonly used in older adults.
Patients given certain oral NSAIDS are much more likely to require hospitalization for gastrointestinal problems than those given low-dose (no more than 3 g/day) acetaminophen. However, the risk was not increased—and may even have been reduced—for patients given a selective NSAID (celecoxib). NSAIDS also can increase the risk of cardiovascular problems and stroke, as well as kidney disease (acute renal failure). Finally, opioid drugs are effective for patients who can't tolerate acetaminophen or NSAIDS. However, the choice of opioids depends on pain intensity, age-related changes in drug metabolism, coexisting medical conditions, and adverse drug events. Treatment with opioids can be associated with higher rates of delirium and falls (often leading to fractures).
These findings were based on a systematic review of the English language literature from January 2001 through June 2012. The study was funded in part by AHRQ (HS17695, HS19461, and HS18721).
More details are in "Adverse effects of analgesics commonly used by older adults with osteoarthritis: Focus on non-opioid and opioid analgesics," by Christine K. O'Neil, Pharm.D., Joseph T. Hanlon, Pharm.D., M.S., and Zachary A. Marcum, Pharm.D., M.S., in the December 2012 The American Journal of Geriatric Pharmacology 10(6), pp. 331-342.