Side effects can limit opioid dosage and reduce quality of life. The purpose of this
systematic review was to assess the management of opioid side effects in the context
of cancer pain management or, in the event that no evidence was available for cancer
pain, for chronic noncancer pain. The side effects studied were constipation, pruritus,
nausea and vomiting, myoclonus, sedation, respiratory depression, and delirium. Opioid
rotation to manage side effects was also studied. For each side effect, we searched
MEDLINE and the Cochrane Controlled Trials Register and identified 657 possible titles
for inclusion. Of these, 67 studies met inclusion criteria for analysis. The lack
of well-designed, randomized controlled trials and the heterogeneity of populations
and study designs made the drawing of firm conclusions difficult and precluded performance
of meta-analysis. The type, strength, and consistency of evidence for available interventions
to manage opioid side effects vary from strong (eg, on the use of naloxone to reverse
respiratory depression or constipation) to weak (eg, changing from the oral to epidural
route of morphine administration to manage sedation). Well-designed trials in the
specified populations are required to furnish clinicians with secure evidence on managing
opioid side effects successfully.