A systematic review published in the
Journal of the American Geriatrics Society looked at evidence with respect to the ‘efficacy, safety, and abuse and misuse potential’ of opioid drugs in older people (>60 years) with non-cancer pain. 43 studies were identified as suitable for inclusion and in these 70% of patients were treated for osteoarthritis. The studies were rather short (median duration 4 weeks) with only 5 lasting longer than 12 weeks. 1
Significant (though modest) reductions in pain and disability and non-significant improvements in sleep and physical quality of life (as measured by SF36) were found by meta-analysis of 18 studies comparing opioid with placebo. Adverse events were common, however, and 1 in 4 patients discontinued the active treatment. Constipation was the commonest adverse event, with nausea, dizziness and somnolence close behind. Misuse or abuse of opioids was found to be uncommon in older patients. High-potency opioids were not found to be more effective in relieving pain than weak or moderate-strength opioids. Long-acting preparations were found to be more effective than shorter-acting preparations.
The short duration of the studies is a particular problem. Patients with osteoarthritis are highly likely to need long-term pain control. Benefits of treatment tend to occur earlier in treatment and adverse effects later – sometimes much later. The authors conclude that it is therefore difficult to make meaningful risk-benefit analyses, and this is congruent with an earlier Cochrane Review
which gave both a number needed to treat and a number needed to harm of 6 for opioid medications. Another study 2 suggesting that long-term use of opioid medication is problematic in older people examined the healthcare records of Medicare beneficiaries in the USA. Fracture events were correlated with prescription of opioids and NSAIDs. 38 fracture events were documented in 4874 NSAID users and 587 events in 12,436 opioid users. The hazard ratio was 4.9 for opioid users compared with NSAID users. Risk was higher in users of short-acting opioids – HR 5.1 as opposed to 2.6 with long-acting preparations. These findings offer no great encouragement to prescribe opioids for older patients with joint pain as an alternative to NSAIDs, and underline the difficulty of prescribing safe and effective pain-relieving treatments for this patient group. So would these patients’ outcomes be any better if they did choose to consult their doctor?! 3