Quaternary derivatives of noroxymorphone which relieve nausea and emesis

Quaternary derivatives of noroxymorphone are used to prevent or relieve nausea and emesis associated with the use of narcotic analgesics without interfering with the analgesic activity of the drugs. A particularly preferred compound is methylnaltrexone. The compound is administered in a concentration between 0.25 mg/kg and 1.0 mg/kg prior to or concurrently with the administration of the narcotic analgesic.