Study Supports Opioid Painkillers For Older Patients
Friday, May 20, 2005
Older pain sufferers and their doctors often shun morphine-based medications such as OxyContin and Percocet, but a new study suggests that those over 60 are often better candidates for the medications than younger patients.
Not only do older people report greater pain relief, but they are much less likely than younger patients to need rapidly escalating dosages to control their pain, the research found.
In the first systematic look at age differences among patients taking opioids, researchers at the University of California at San Francisco pain clinic found that on average, patients under 50 required medication twice as strong as that needed by patients over 60. After almost two years, the older patients reported they still got relief on the low doses, while the younger patients reported little pain relief even after their dosages were increased.
"Because of the continuing stigma associated with opioids among many older people, the group that stands to benefit the most from the pain relief they give are getting the least," lead author Pamela Palmer said in a telephone interview. "Doctors are reluctant to prescribe the opioids, and seniors are reluctant to take them."
One reason that older people avoid opioids, she said, is that they fear they will want higher and higher doses as they become "tolerant" of the drug and will become addicted. But the study, she said, showed that older patients develop tolerance very slowly.
Palmer said older people in pain are being poorly served by doctors because morphine-based drugs at moderate doses have less-serious side effects than other painkillers. The primary side effects of opioids are nausea and constipation, while the possible risks of COX-2 inhibitors and other anti-inflammatory drugs include heart and kidney damage and gastric ulcers.
The new study, published in the journal Anesthesia and Analgesia, examined the medical records of 206 patients who had been treated for two years with morphine-based drugs for severe pain not related to cancer. The patients were divided into two groups -- those over 60 and those under 50.
Patients in both groups started with similar dosages of the painkillers, and both reached their top dose in about 15 months. The average peak dose, however, was twice as high for those under 50 as for those over 60.
Patients in both groups rated their pain levels at the beginning and end of treatment. The older group reported improvement, but the younger group did not, even though their dosages had increased substantially.
Palmer, director of anesthesia for the UCSF Pain Management Center, said older people are often under the mistaken belief that moderate use of opioids will lead to addiction.
The study found that younger pain patients did tend to need ever larger doses to control their pain, and after two years they were taking twice as much medication as the older patients. At higher dosages, opioids are more likely to become addictive.
In a companion study, researchers found a similar phenomenon in rats, with younger animals developing tolerance to opioids much more quickly and intensely than older animals. That study found that 3-week-old rats developed tolerance to opioid drugs five times as fast as 6-month-old rats.