High opioid adverse event risk after breast cancer treatment extends beyond misuse
medwireNews: Older women who are prescribed opioids within a year of finishing active treatment for breast cancer have an immediately elevated risk for serious adverse events, including, but not limited to, those associated with opioid misuse, suggests a review of medical records.
“Opioids remain a mainstay of cancer pain management; however, increasing evidence indicates that the benefits of long-term opioid use for cancer pain may be limited,” say Andrew Roberts (University of Kansas Medical Center, Kansas City, USA) and colleagues in JAMA Network Open.
They analyzed data pertaining to 38,310 women with a mean age of 74.3 years, all of whom were prescribed opioids within a year of completing active anticancer treatment for stage 0 to III breast cancer.
Over the 12-month follow-up period, 3242 opioid-associated adverse events occurred, translating into 0.237 events per 1000 patient–days. These events included 1329 falls or fractures, 927 serious infections, 710 cardiovascular events, and 322 gastrointestinal events.
Additionally, 130 adverse events associated with opioid misuse occurred, namely diagnoses of opioid dependence, abuse, or poisoning, equating to 0.010 events per 1000 patient–days. And in total there were 9228 instances of patients being hospitalized for any reason, at 0.675 hospitalizations per 1000 patient–days.
Analysis of exposure to opioids on the day preceding an adverse event revealed that taking opioids was associated with an immediate increased risk for adverse drug events. Specifically, opioid exposure was associated with a 14.62-fold increased risk for adverse events related to substance misuse.
“As efforts to increase opioid safety for treating cancer pain increases, it is important for clinicians to recognize that opioid-related risks in this population extend beyond misuse, overdose, and opioid use disorder,” emphasize Roberts and fellow researchers.
Indeed, “[o]ther adverse drug events associated with opioid use were 23.7-fold more common than adverse drug events related to opioid misuse,” they point out.
Current opioid exposure, compared with days without exposure, was associated with an immediate 2.50-fold increased risk for adverse events not related to opioid misuse, including serious infections (adjusted risk ratio [aRR]=3.26), gastrointestinal events (aRR=2.87), cardiovascular events (aRR=2.38), and falls or fractures (aRR=2.34), as well as a nearly threefold immediate increased risk for hospitalization.
Sensitivity analyses showed a consistent dose–response; high opioid doses (at least 50 mg morphine equivalent dose per day) increased the risk for any adverse drug event 3.40-fold relative to no opioid exposure, while low doses (between 1 and 49 mg) were associated with a 2.29-fold increased risk.
The researchers conclude: “Clinicians should carefully weigh the benefits and comprehensive risks of opioid therapy in older adult survivors of breast cancer who have completed active breast cancer treatment.”
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