Table 2 : Adverse effects associated with the use of opioids.

Respiratory depression
  • Dose-dependent
  • Decreased minute ventilation via decreased respiratory rate
  • Enhanced by CNS depressants, renal insufficiency, respiratory acidosis
  • Tolerance develops with repeated dosing
  • Treated with naloxone

  • Dose-dependent
  • May precede analgesia
  • Enhanced by CNS depressants
  • Treated with naloxone

GI Side Effects
  • Nausea/vomiting
    • Treated with serotonin and dopamine antagonists and low-dose steroids
  • Decreased motility and constipation
    • Tolerance does NOT develop with repeated dosing
    • Treated with naloxone and methylnaltrexone
  • Biliary spasm

  • NOT due to histamine release
  • Difficult to treat without reversing analgesic effects with opioid antagonists

Less Common Adverse Effects
  • Urinary retention
    • Treated with naloxone and methylnaltrexone
  • Confusion/mental status changes
    • Common in elderly patients
  • Bradycardia
    • Exacerbated by concurrent use of beta-blockers and calcium-channel blockers
  • Muscle rigidity
    • Seen with high doses and often requires neuromuscular blockade

A. Quraishi et al.Journal of Anesthesiology and Clinical Science  2013 2:1DOI : 10.7243/2049-9752-2-1