Intravenous ondansetron for the control of opioid-induced nausea and vomiting

This randomized, double-masked, placebo-controlled, multicenter trial was c onducted in 9 countries to assess the safety and efficacy of 2 doses of int ravenous ondansetron (8 and 16 mg) for the control of opioid-induced nausea and vomiting. A total of 2574 nonsurgical patients who presented with pain requiring treatment with an opioid analgesic agent participated in this tr ial. The most common presenting painful condition was back or neck pain, re ported by approximately one third of patients. A total of 520 patients (317 females, 203 males) developed nausea or vomiting after opioid administrati on and were randomly assigned to receive a single dose of 1 of 3 study trea tments: placebo (n = 94), ondansetron 8 mg (n = 215), or ondansetron 16 mg (n = 211). Ondansetron 8 and 16 mg led to complete control of emesis in 134 of 215 patients (62.3%) and 145 of 211 patients (68.7%), respectively. Res ults with both doses were significantly better than those seen with placebo (43 of 94 patients [45.7%]). Complete control of nausea was achieved in 6. 8% of placebo patients, 14.8% of ondansetron 8-mg-treated patients, and 19. 4% of ondansetron 16-mg-treated patients; only ondansetron 16 mg was signif icantly better than placebo (P = 0.007). Significantly more patients who re ceived ondansetron 8 mg than patients who received placebo were satisfied/v ery satisfied with their antiemetic treatment, as assessed by 4 patient-sat isfaction questions. Significantly more patients who received ondansetron 1 6 mg compared with placebo were satisfied/very satisfied on 2 of 4 satisfac tion questions. In conclusion, based on the observed incidence of opioid-in duced nausea and vomiting in this study, it may be more appropriate to trea t symptoms on occurrence rather than administering antiemetic agents prophy lactically. The results of this study demonstrate that intravenous ondanset ron in doses of 8 or 16 mg is an effective antiemetic agent for the control of opioid-induced nausea and vomiting in nonsurgical patients requiring op ioid analgesia for pain.