Non-analgesic effects of opioids: opioid-induced nausea and vomiting: mechanisms and strategies for their limitation.

Nausea and vomiting are common gastrointestinal symptoms following opioid administration, for either chronic or acute pain management. As a consequence, patients' dissatisfaction has a negative impact on treatment efficacy. A number of mechanisms have been identified, involving both central and peripheral sites. This article will review the pathophysiology of opioid-induced nausea and vomiting and the various pharmacological treatments currently available for its management. Preventive strategies and therapeutic approaches are evaluated in the perioperative setting and in chronic pain. Newer drugs include second generation serotonin receptor antagonists (palonosetron) and neurokinin-1 (NK-1) antagonists (aprepitant).