In Lynch and Fischer’s comparison1 of our research on opioid-related mortality2 with previous research on the safety of nonsteroidal anti-inflammatory drugs (NSAIDs),3 they imply that opioids are safer than NSAIDs.
We have shown that the opioid-related mortality rate among public drug plan beneficiaries who are prescribed opioids for noncancer pain is 1.86 per 1000 (95% CI 1.64 to 2.10 per 1000) within 2 years and 7.92 per 1000 among the small proportion of patients who are prescribed more than 200 mg of morphine or equivalent per year.4 The all-cause mortality rate among patients prescribed opioids for noncancer pain is approximately 1% per year—roughly 5 times higher than in patients who are not prescribed opioids.
The opioid-related mortality rate of 27.2 per 1 000 0002 reported in our study and cited by Lynch and Fischer is a population-level statistic that includes all Ontarians in the denominator, not just those prescribed opioids. It is incorrect and misleading to contrast this with the rate of NSAID-related mortality in patients who are treated with NSAIDs.
Only a well-designed randomized trial would definitively assess the relative safety of opioids and NSAIDs. No such study exists, and we must therefore look to observational studies for the best available evidence. In a high-quality cohort study, Solomon et al recently showed that older adults who were prescribed opioids were almost twice as likely to die as patients prescribed NSAIDs were.5
Based on these data as well as our own, we believe it is reasonable to conclude that, as currently used in clinical practice, opioids are more dangerous than NSAIDs. This finding is consistent with recommendations from the World Health Organization that acetaminophen and NSAIDs be used before opioids.6
Footnotes
Competing interests
None declared
References
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