Study finds different opioids offer variable safety in older adults with noncancer pain

February 1, 2011

Different opioids had different safety profiles when administered to older adults for noncancer pain, according to results from a new study published in the Archives of Internal Medicine.

Key Points

Different opioids had different safety profiles when administered to older adults for noncancer pain, according to results from a new study published in the Archives of Internal Medicine.

"Almost no information exists about the comparative safety of opioids regarding serious adverse events, such as fractures, cardiovascular events, hospitalizations for gastrointestinal toxic effects, or mortality," noted researchers from Brigham and Women's Hospital in Boston, in their paper. They further stressed, "This vacuum of information presents a major problem for patients and providers."

To address this paucity of information, the researchers conducted an observational study using data from 2 US states that provided unrestricted coverage of opioids to Medicare beneficiaries through state-run pharmaceutical assistance programs. Researchers were able to identify new initiators of opioid therapy for noncancer pain, and then propensity-score match patients receiving codeine phosphate, hydrocodone bitartrate, oxycodone hydrochloride, propoxyphene hydrochloride, and tramadol hydrochloride in order to assure that the 6,275 patients in each of the 5 opioid groups had similar baseline characteristics.

According to Daniel H. Solomon, MD, MPH, lead author on this new paper, "This study's findings do not agree with a commonly held belief that all opioids are associated with similar risk." He stressed, "Our findings regarding cardiovascular risk were surprising and require validation in other data sets."

In an accompanying editorial, William C. Becker, MD, and Patrick G. O'Connor, MD, MPH, from the Yale University School of Medicine, New Haven, Conn., noted, "In contrast to the cardiovascular findings, elevated fracture risk with opioid use has solid biological plausibility through both of the mechanisms cited by the authors: increased fall risk and, although less relevant in this cohort of elderly initiates of opioid therapy, central effects on the hypothalamic-pituitary-adrenal axis that suppress androgen and estradiol production." Moreover, Drs Becker and O'Connor emphasized, "That the weaker opioids tramadol and propoxyphene had a decreased risk of fracture compared with the stronger opioids hydrocodone and oxycodone suggests a direct relationship between potency of the opioid and risk of falling and possibly decreased bone mass."

The study's researchers concluded their report by suggesting that the increased risk of various adverse events seen upon treating older adults for noncancer pain with opioids should be considered clinically relevant and should prompt caution and further study. However, they remarked, "We doubt that the comparative safety of multiple opioids will ever be adequately tested in a randomized controlled trial."

SOURCES

Solomon DH, Rassen JA, Glynn RJ, et al. The comparative safety of opioids for nonmalignant pain in older adults. Arch Intern Med. 2010;170(22):1979–1986.

Becker WC, O'Connor PG. The safety of opioid analgesics in the elderly: new data raise new concerns: comment on "The comparative safety of opioids for nonmalignant pain in older adults." Arch Intern Med. 2010;170(22):1986–1988.