Back pain affects most adults, causes disability for some, and is a common reason for seeking healthcare. In the United States,
opioid prescription for
low back pain has increased, and
opioids are now the most commonly prescribed
drug class. More than half of regular
opioid users report
back pain. Rates of
opioid prescribing in the US and Canada are two to three times higher than in most European countries. The
analgesic efficacy of
opioids for acute
back pain is inferred from evidence in other
acute pain conditions.
Opioids do not seem to expedite return to work in injured workers or improve functional outcomes of acute
back pain in primary care. For chronic
back pain, systematic reviews find scant evidence of efficacy. Randomized controlled trials have high dropout rates, brief duration (four months or less), and highly selected patients.
Opioids seem to have short term
analgesic efficacy for chronic
back pain, but benefits for function are less clear. The magnitude of
pain relief across chronic non-
cancer pain conditions is about 30%. Given the brevity of randomized controlled trials, the long term effectiveness and safety of
opioids are unknown. Loss of long term efficacy could result from drug tolerance and emergence of
hyperalgesia. Complications of
opioid use include addiction and overdose related mortality, which have risen in parallel with prescription rates. Common short term side effects are
constipation,
nausea, sedation, and increased risk of falls and fractures. Longer term side effects may include depression and sexual dysfunction. Screening for high risk patients, treatment agreements, and urine testing have not reduced overall rates of
opioid prescribing, misuse, or overdose. Newer strategies for reducing risks include more selective prescription of
opioids and lower doses; use of prescription monitoring programs; avoidance of co-prescription with
sedative hypnotics; and reformulations that make drugs more difficult to snort,
smoke, or inject.