Opioid pain medications safe for older patients but not younger

A new study shows narcotic medications can safely and effectively ease severe, chronic pain in patients older than 60. However, patients younger than 50 are likely to want to rapidly increase their dose, which poses serious health consequences.

Based on their findings, researchers from University of California at San Francisco suggest opioid pain medications may be under-prescribed in older patients, yet pose unique risks for younger patients. Opioids are a class of drugs that includes morphine, methadone and oxycodone (sold as OxyContin, Percocet among others) that are used for unremitting pain. However, doctors worry giving patients opioids leads to them needing constant increases in doses because of the tolerance they develop.

Researchers examined medical records of 206 patients who had been treated with opioids for two years for severe pain caused by nerve damage, arthritis, fibromyalgia or related conditions.

They found patients ages 60 and older faced a much lower risk of opioid dose escalation than did younger patients. Both groups started with similar doses of morphine-like drugs, and both took about 14 to 15 months to reach their peak dose. However, the peak dose of the younger group was more than twice that of the older group.

Also, based on self-assessment scores, older patients received long-term pain relief from the drugs and younger patients did not.

The researchers wanted to confirm the age-related differences in tolerance in an animal study and found consistent results. They found the youngest rats experienced drug tolerance more than five-times sooner than the oldest rats.

The difference between older and younger patients may be the result of molecular changes in neurons that occur with aging, speculate the researchers. They say this is an important area of future study.

The study authors point out that long-term, moderate opioid use does not pose the increased risk for heart or kidney damage for older patients that some Cox-2 inhibitors do, which is a significant concern for many older pain patients. Yet, younger patients are at much lower risk for heart attack and gastrointestinal bleeding, so they may be better candidates for these newer non-steroidal anti-inflammatory drugs (NSAIDs).

Researchers conclude opioids appear to be safe and effective for older patients to treat long-lasting serious pain, while young patients should be cautious of using daily opioids to treat chronic pain.

SOURCE: To be published in an upcoming issue of Anesthesia and Analgesia