Prevention of nausea and vomiting with granisetron, droperidol and metoclopramide during and after spinal anaesthesia for caesarean section: A randomized, double-blind, placebo-controlled trial

Background: Nausea and vomiting during and after spinal anaesthesia for caesarean section are distressing to the patient. This study was undertaken to evaluate the efficacy and safety of granisetron, droperidol and metoclopramide for the prevention of nausea and vomiting in parturients undergoing caesarean section under spinal anaesthesia.
Methods: In a randomized, double-blind, placebo-controlled trial, 120 patients received granisetron 3 mg, droperidol 1.25 mg, metoclopramide 10 mg or placebo (saline) ( n =30 of each) i. v. immediately after clamping of the foetal umbilical cord. Nausea, vomiting and safety assessments were performed during and after spinal anaesthesia for caesarean section.
Results: The incidence of intraoperative, post-delivery nausea and vomiting was 13%, 17%, 20% and 63% after administration of granisetron, droperidol, metoclopramide and placebo, respectively; the corresponding incidence during 0–3 h after surgery was 7%, 27%, 27% and 43%; the corresponding incidence during 3–24 h after surgery was 7%, 20%, 23% and 37% ( P <0.05; overall Fisher's exact probability test). No clinically important adverse events were observed in any of the groups.
Conclusion: Granisetron is highly effective for preventing nausea and vomiting during and after spinal anaesthesia for caesarean section. Droperidol and metoclopramide are effective for the prevention of intraoperative, post-delivery emesis, but are ineffective for the reduction of the incidence of postoperative emesis.     

RETRACTED ARTICLE: Prevention of PONV with granisetron, droperidol or metoclopramide in patients with postoperative emesis

Purpose

A high incidence of postoperative nausea and vomiting (PONV) has been noted in patients with a history of postoperative emesis. This study was undertaken to compare the efficacy of granisetron, droperidol and metoclopramide, in the prevention of PONV in such patients undergoing general anaesthesia for major gynaecological surgery.

Methods

In a randomised, double-blind study, 90 female patients received 2.5 mg granisetron, 1.25 mg droperidol or 10 mg metoclopramide (n = 30 of each)iv immediately before induction of anaesthesia. The same standard general anaesthetic technique, which consisted of isoflurane in nitrous oxide and oxygen, was used. Nausea, vomiting and safety assessments were performed continuously during the first 24 hr after anaesthesia.

Results

The incidence of PONV was 20% with granisetron, 57% with droperidol and 60% with metoclopramide (P < 0.05; overall Fisher’s exact probability test). No clinically adverse events were observed in any group.

Conclusion

Granisetron is more effective than droperidol or metoclopramide in preventing PONV in female patients with a history of postoperative emesis.     

Granisetron-droperidol combination for the prevention of postoperative nausea and vomiting in female patients undergoing breast surgery

We have compared the efficacy and safety of the combination granisetron- droperidol with each antiemetic alone in preventing postoperative nausea and vomiting (PONV) after breast surgery. In a randomized, double-blind study, 150 female patients received granisetron 3 mg, droperidol 1.25 mg or granisetron 3 mg with droperidol 1.25 mg (n = 50 each) i.v., immediately before induction of anaesthesia. A standard general anaesthetic technique was used. The incidence of PONV during the first 24 h after anaesthesia was 18% with granisetron, 38% with droperidol and 4% with the granisetron-droperidol combination (P < 0.05; overall Fisher's exact probability test). We conclude that the granisetron-droperidol combination was more effective than each antiemetic alone in the prevention of PONV in female patients undergoing breast surgery.      

Prevention of nausea and vomiting in female patients undergoing breast surgery: A comparison with granisetron, droperidol, metoclopramide and placebo

Background : Breast surgery is associated with a relatively high incidence of postoperative nausea and vomiting (PONV). This study was undertaken to evaluate the efficacy of granisetron, droperidol and metoclopramide for preventing PONV after breast surgery.
Methods : In a randomized, double-blind, placebo-controlled trial, 120 female patients received granisetron 40μg.kg^-1, droperidol 1.25 mg, metoclopramide 10 mg or placebo (saline) (n=30 for each) intravenously immediately before the induction of anaesthesia. A standard general anaesthetic technique was employed throughout. Postoperatively, during the first 24 h after anaesthesia, the incidence of PONV and adverse events was recorded.
Results : The incidence of PONV was 17% with granisetron, 37% with droperidol, 43% with metoclopramide and 50% with placebo ( P <0.05; overall Fisher's exact probability test). The incidence of adverse events was not different among the groups.
Conclusion : Granisetron is highly effective for reducing the incidence of PONV in female patients undergoing breast surgery. Droperidol and metoclopramide are ineffective in this population.     

Prophylactic anti-emetic therapy with granisetron, droperidol and metoclopramide in female patients undergoing middle ear surgery

The efficacy of granisetron, droperidol and metoclopramide for the prevention of postoperative nausea and vomiting in female patients undergoing middle ear surgery was compared. In a randomised, double-blind study, 180 patients received granisetron 40 micrograms.kg-1, droperidol 20 micrograms.kg-1 or metoclopramide 0.2 mg.kg-1 given intravenously immediately before induction of anaesthesia (n = 60 for each). A standardised general anaesthetic technique was employed throughout. A complete response, defined as no postoperative nausea and vomiting and no need for another rescue anti-emetic, during the first 3 h after anaesthesia was achieved in 83%, 58% and 55% of patients who had received granisetron, droperidol and metoclopramide, respectively. The corresponding incidence during the next 21 h after anaesthesia was 85%, 54% and 47% (p < 0.05). No clinically important adverse effects were observed in any of the groups. We conclude that prophylactic therapy with granisetron is superior to droperidol or metoclopramide in the prevention of postoperative nausea and vomiting after middle ear surgery.     

RETRACTED ARTICLE: Reduction of postoperative nausea and vomiting with granisetron

The antiemetic effects of granisetron, a selective 5-hydroxy-tryptamine type 3 receptor antagonist, on postoperative nausea and vomiting were studied and compared with placebo and metoclopramide in 60 patients undergoing general anaesthesia for major gynaecological surgery. The patients received a single iv dose of either granisetron (3 mg, n = 20) metoclopramide (10 mg, n = 20), or placebo (saline, n = 20) immediately after recovery from anaesthesia. The effects were assessed during the first three and the next 21 hr after recovery from anaesthesia by means of a nausea and vomiting score; 0 = no emetic symptoms, 1 = nausea, 2 = vomiting. The mean scores during 0–3 hr were 0.8, 0.1 and 0.1 after administration of placebo, metoclopramide and granisetron, respectively; the corresponding scores during 3–24 hr were 0.6, 0.5 and 0.1. The scores of the metoclopramide and the granisetron groups were different from the placebo group in the first three hours (P < 0.05). Although there were no differences in the scores during 0–3 hr between the metoclopramide and the granisetron groups, there were differences during 3–24 hr (P < 0.05). It is concluded that granisetron is superior to metoclopramide in the long-term prevention of postoperative nausea and vomiting after anaesthesia.     

RETRACTED ARTICLE: Prevention of PONV with granisetron, droperidol and metoclopramide in female patients with history of motion sickness

Purpose

Motion sickness is one of the patient-related factors associated with postoperative nausea and vomiting (PONV). This study was undertaken to assess the efficacy of granisetron, droperidol and metoclopramide for preventing PONV in female patients with a history of motion sickness undergoing major gynaecological surgery.

Methods

In a prospective, randomized, placebo-controlled, double-blind study. 120 patients received either 1.25 mg dropendol. 10 mg metoclopramide, 40 μkg granisetron or placebo (saline)iv immediately before induction of anaesthesia. A standardized anaesthetic technique and postoperative analgesia were used in all patients. During the first 24 hr after anaesthesia, the incidence of PONV and adverse events were recorded by nursing-staff.

Results

The treatment groups were similar for patient demographics, types of surgery, anaesthetics administered and opioid given. The incidence of PONV was 70%, 50%. 57% and 23% in the placebo, droperidol, metoclopramide and granisetron groups, respectively (P < 0.05; overall χ² test). No difference in the incidence of adverse events was observed in either group.

Conclusion

Granisetron is a better prophylactic antiemetic than dropendol or metoclopramide in female patients with a history of motion sickness undergoing major gynaecological surgery.     

Prevention of post-operative nausea and vomiting with combined granisetron and droperidol in women undergoing thyroidectomy

We have compared the efficacy and safety of combined granisetron and droperidol with each anti-emetic alone for preventing post-operative nausea and vomiting after thyroidectomy. In a prospective, randomized, double-blind study, 180 women received granisetron 40 micrograms kg-1, droperidol 20 micrograms kg-1, or granisetron 40 micrograms kg-1 plus droperidol 20 micrograms kg-1 (n = 60 of each) intravenously immediately before induction of anaesthesia. A standard general anaesthetic technique and post-operative analgesia were used. A complete response, defined as no post-operative nausea and vomiting and no need for another rescue anti-emetic, during the first 24 h after anaesthesia occurred in 88%, 60% and 98% of patients who had received granisetron, droperidol and granisetron plus droperidol (P < 0.05; overall Fisher's exact probability test). No clinically important adverse events due to the drugs were observed in any of the groups. In summary, prophylactic use of combined granisetron and droperidol is more effective than each drug alone for the prevention of post-operative nausea and vomiting in female patients undergoing thyroidectomy.     

RETRACTED ARTICLE: Antiemetic effects of granisetron on postoperative nausea and vomiting in patients with and without motion sickness

Purpose

This randomized, placebo-controlled, double-blind study was to evaluate the effects of granisetron, a selective 5-hydroxytryptamine type 3 receptor antagonist, for preventing postoperative nausea and vomiting in 110 patients with (n = 50) and without (n = 60) a history of motion sickness undergoing general anaesthesia for major gynaecological surgery.

Methods

The patients received a single dose of either granisetron (40 μg · kg^?1) or placebo (saline) iv over 2–5 min immediately before induction of anaesthesia. Postoperatively, during the first 24 hr after anaesthesia, the frequencies of nausea and vomiting were recorded.

Results

Except for a positive history of motion sickness, the treatment groups were similar for patient characteristics, types of surgery, anaesthetics administered and opioids given. Postoperatively, the frequency of nausea was 44% and 16% after administration of placebo and granisetron in patients with motion sickness, and was 30% and 7% in patients without it, respectively; the corresponding frequencies of vomiting were 28%, 8%, 13% and 3%. The incidence of adverse events postoperatively were not different among the groups.

Conclusion

These results suggest that preoperative prophylactic administration of granisetron is effective and safe for preventing postoperative nausea and vomiting in patients with motion sickness as well as in patients without it.     

RETRACTED ARTICLE: Prophylactic antiemetic therapy with granisetron-droperidol combination in patients undergoing laparoscopic cholecystectomy

Purpose

A relatively high incidence of postoperative nausea and vomiting (PONV) occurs in patients undergoing laparoscopic cholecystectomy. This study was undertaken to compare the efficacy of granisetron-droperidol combination with each drug alone for the prevention of PONV after laparoscopic cholecystectomy.

Methods

In a randomized, double-blind manner, 150 female inpatients received 3 mg granisetron (Group G), 1.25 mg droperidol (Group D) or 3 mg granisetron plus 1.25 mg droperidol (Group GD) (n = 50 for each)iv immediately before the induction of anaesthesia. The same standard general anaesthetic technique, which consisted of isoflurane and nitrous oxide in oxygen, was used. Nausea, vomiting and safety assessments were performed continuously during the first 24 hr after anaesthesia.

Results

Complete response, defined as no PONV and no administration of rescue antiemetic medication, was 86% in Group G, 64% in Group D and 98% in Group GD (P = 0.03 vs Group G,P = 0.001 vs Group D). No clinically adverse events were observed in any group.

Conclusion

Granisetron-droperidol combination is more effective than each antiemetic alone in the prevention of PONV after laparoscopic cholecystectomy.     

Ondansetron or droperidol for prophylaxis of nausea and vomiting after intrathecal morphine

BACKGROUND AND OBJECTIVE: There is a controversy regarding the best drug for prevention of nausea and vomiting in patients receiving intrathecal morphine. The aim of this study was to examine efficacy and tolerability of droperidol compared with ondansetron for the prevention of morphine-induced nausea and vomiting. METHODS: In a randomized, placebo-controlled trial, 120 women undergoing Caesarean section under spinal anaesthesia with intrathecal morphine 0.1 mg received intravenous ondansetron 4 mg (n = 40), droperidol 1.25 mg (n = 40) or saline (n = 40) immediately after umbilical-cord clamping. Nausea and vomiting were graded according to intensity at 1, 2, 4, 6, 12 and 24 h. RESULTS: Nausea or vomiting occurred in 14 patients (35%) in the placebo group, 4 (10%) in the ondansetron group and 10 (25%) in the droperidol group; the difference between ondansetron and placebo was statistically significant (P = 0.007). Eleven of the 14 placebo patients (27.5%) vomited, compared with none of the 4 ondansetron patients (vs. placebo, P = 0.0004) and 5 of the droperidol patients (vs. placebo, P = 0.18). Three of the 14 placebo patients (7.5%) were nauseous, compared with 4 (10%) receiving ondansetron and 5 (12.5%) receiving droperidol. CONCLUSIONS: Ondansetron was effective in reducing the incidence of nausea and vomiting in patients receiving intrathecal morphine for Caesarean section.     

Postoperative nausea and vomiting after breast surgery: efficacy of prophylactic ondansetron and droperidol in a randomized placebo-controlled study

Postoperative nausea and vomiting (PONV) is a common adverse phenomenon following breast surgery. The efficacy of ondansetron and droperidol in preventing post-operative nausea and vomiting in women undergoing breast surgery was compared in this randomized, double-blind, placebo-controlled study. Altogether 207 women were randomly assigned to receive either a single intravenous dose of droperidol (1.25 mg) (n = 69), ondansetron (8 mg) (n = 67) or saline (n = 71) immediately after induction of general anaesthesia with thiopental, fentanyl, atracurium, nitrous oxide in oxygen and isoflurane. Complaints of nausea, vomiting and requests for rescue antiemetics were recorded during a 24-h period postoperatively. During the initial 2 h in the postanaesthesia care unit, the incidence of postoperative nausea and vomiting was 15%, 6% and 12% in the placebo, droperidol and ondansetron groups, respectively (NS). The incidence of post-operative nausea and vomiting during the first 24 h was 61%, 48% and 45% in the placebo, droperidol and ondansetron treatment groups, respectively (NS). Postoperative analgesic requirements and the length of stay in the post-anaesthesia care unit were equal in all three treatment groups. It is concluded that the intravenous pretreatment with single doses of ondansetron or droperidol did not substantially prevent postoperative nausea and vomiting after breast surgery.     

Placebo-controlled comparison of dolasetron and metoclopramide in preventing postoperative nausea and vomiting in patients undergoing hysterectomy

BACKGROUND AND OBJECTIVE: In a randomized, placebo-controlled, double-blind trial, we compared the efficacy of dolasetron and metoclopramide in preventing postoperative nausea and vomiting in women undergoing hysterectomy. METHODS: Patients were allocated randomly to one of three groups: group A (n = 50) received 50 mg dolasetron orally, group B (n = 50) received 20 mg metoclopramide intravenously and placebo orally, group C (n = 50) received placebo orally. If patients complained of retching or vomiting, or if patients demanded an antiemetic, 1.25 mg droperidol was administrated intravenously. To quantify postoperative nausea and vomiting the following score was used: 0 = no nausea, 1 = nausea, 2 = retching, 3 = single vomiting, 4 = multiple vomiting. The Raatz test was used to analyse postoperative nausea and vomiting (PONV) scores. RESULTS: Dolasetron reduced the postoperative nausea and vomiting score significantly (P < 0.02 vs. metoclopramide; P < 0.0001 vs. placebo). Metoclopramide also reduced the postoperative nausea and vomiting score (P < 0.02 vs. placebo). Fisher's exact test showed a significant reduction of vomiting in the dolasetron group compared with metoclopramide-treated patients (P < 0.007) and placebo-treated patients (P < 0.000006) and a significantly lower rate of nausea in comparison to the placebo group (P < 0.009). There were no significant differences between the metoclopramide and the placebo groups (in Fisher's exact test). The use of postoperative droperidol per patient was significantly lower in the dolasetron group (P < 0.04 vs. metoclopramide; P < 0.0001 vs. placebo) than in the metoclopramide (P < 0.02 vs. placebo) and in the placebo groups. CONCLUSIONS: Oral dolasetron is more effective than either metoclopramide given intravenously or placebo for preventing vomiting after hysterectomy. It also was significantly superior to either metoclopramide or placebo concerning the PONV score and the need for droperidol rescue.     

Dexamethasone for preventing nausea and vomiting associated with epidural morphine: a dose-ranging study

We conducted a dose-ranging study of dexamethasone for preventing nausea and vomiting within the first 24 h after the administration of epidural morphine. Two hundred twenty-five women (n = 45 in each of the five groups) undergoing simple abdominal total hysterectomy under epidural anesthesia were enrolled in this randomized, double-blind, placebo-controlled study. When the incision closure was completed, patients received IV dexamethasone, 10 mg, 5 mg, or 2.5 mg; IV droperidol 1.25 mg; or saline 2 mL. All patients received epidural morphine 3 mg for postoperative analgesia. We found that patients who received dexamethasone 5 mg or 10 mg or droperidol 1.25 mg were significantly different from those who received saline alone in the following variables: the total incidence of nausea and vomiting, the incidence of more than four vomiting episodes, the number of patients requiring rescue antiemetics, the total number of patients with no vomiting and/or no antiemetic medication (P < 0.05 to P < 0.01). The differences among dexamethasone 10 mg and 5 mg and droperidol 1.25 mg were not significant. Dexamethasone 2.5 mg was ineffective. In conclusion, because dexamethasone 5 mg was as effective as 10 mg as an antiemetic, we recommend the smaller dose for preventing nausea and vomiting associated with epidural morphine. IMPLICATIONS: We conducted a dose-ranging study of dexamethasone for preventing nausea and vomiting within the first 24 h after the administration of epidural morphine. We found that dexamethasone 5 mg was as effective as 10 mg. We recommend the smaller dose for this purpose.     

Comparison of ondansetron and droperidol in the prevention of postoperative nausea and vomiting after laparoscopic surgery in women

Background : Women undergoing laparoscopic surgery are susceptible to postoperative nausea and vomiting (PONV). Ondansetron and droperidol are useful antiemetics. This study was designed to ascertain primarily the relative difference in efficacy of ondansetron and droperidol and secondarily between these drugs and placebo in the prevention of PONV after laparoscopic surgery. Methods : The prophylactic antiemetic efficacy of ondansetron and droperidol was compared in a prospective, randomised, double–blind, placebo–controlled trial of 439 female inpatients scheduled for laparoscopic surgery. During induction of standardised general anaesthesia the patients received intravenously either ondansetron 8 mg (n=195), droperidol 1.25 mg (n=193) or placebo (n=51). The occurrence of nausea, vomiting, sideeffects and the need for rescue antiemetic medication were recorded for 24 h postoperatively. Results : The proportion of patients with nausea was 48%, 50% and 67% in the ondansetron, droperidol and placebo groups, respectively; with a significant difference when both ondansetron (P=0.02) and droperidol (P=0.04) were compared with placebo. Vomiting occurred in 18%, 26% and 37% of the patients in the three groups, respectively (P=0.05 between ondansetron and droperidol, P=0.004 between ondansetron and placebo, P=0.16 between droperidol and placebo). The proportion of patients given rescue medication was 34%, 28% and 49%, respectively (P=0.23 for ondansetron and droperidol, P=0.07 for ondansetron and placebo, P=0.007 for droperidol and placebo). During early recovery the patients treated with ondansetron were significantly more alert than after droperidol. Serious side–effects were not observed. Headache was significantly more common after ondansetron than after droperidol treatment. Conclusions : The efficacy of prophylactic ondansetron and droperidol in reducing postoperative nausea associated with laparoscopic surgery in female inpatients was similar, but ondansetron appeared to be slightly more efficient than droperidol in preventing vomiting. Ondansetron and droperidol were both significantly better than placebo in the prophylaxis of PONV.     

RETRACTED ARTICLE: Optimal anti-emetic dose of granisetron for preventing post-operative nausea and vomiting

In order to determine the optimal effective dose of granisetron for preventing postoperative nausea and vomiting, the drug was administered in doses of either 20, 40 or 60 μg sd kg^?1. The efficacy of granisetron was evaluated in a randomized, double-blind comparison with placebo in 100 patients undergoing general anaesthesia for major gynaecological surgery. The patients received a single dose of either granisetron or placebo (saline) iv immediately after recovery from anaesthesia. The effects were assessed during the 24 hr after recovery from anaesthesia by means of a nausea and vomiting score; 0 = no emetic symptoms, 1 = nausea, 2 = vomiting. The treatment groups were similar for patient characteristics, surgical procedures and anaesthetics administered. The mean scores were 0.7, 0.6, 0.2 and 0.2 after administration of placebo, granisetron 20, 40 and 60 μg · kg^?1, respectively. Granisetron 40 μg · kg^?1 was as effective as 60 μg · kg^?1 and both resulted in reduction of the scores compared with placebo and granisetron 20 μg · kg^?1 (P < 0.05). In conclusion, granisetron 40 μg · kg^?1 is considered to be the appropriate dosage for preventing postoperative emesis after anaesthesia.     

Double-blind comparative study of droperidol, granisetron and granisetron plus dexamethasone as prophylactic anti-emetic therapy in patients undergoing abdominal, gynaecological, breast or otolaryngological surgery

In this double-blind study the clinical efficacy of a single pre-operative intravenous dose of droperidol 1.25 mg (137 patients), granisetron 1 mg (130 patients) and granisetron 1 mg plus dexamethasone 5 mg (130 patients) was investigated for the prevention of postoperative nausea and vomiting after gynaecological surgery, breast surgery, abdominal surgery and ear, nose and throat surgery. The incidence of nausea in the first 24 h postoperatively was 52% in the droperidol group, 48% in the granisetron group and 34% with the combination, respectively. Both granisetron and granisetron/dexamethasone performed better than droperidol in their effects on vomiting or combined nausea and vomiting (incidence in the first 24 h 22%, 18% and 42%, respectively). The number of emetic episodes during the 5-day study period was significantly higher in the droperidol group (198) than in the granisetron (73) or combination group (78).     

Prevention of postoperative nausea and vomiting in female patients during menstruation: comparison of droperidol, metoclopramide and granisetron

The incidence of postoperative nausea and vomiting (PONV) is high in women during menstruation. We have compared the efficacy of droperidol, metoclopramide and granisetron in the prevention of PONV in female patients during menstruation undergoing major gynaecological surgery. In a randomized, double-blind study, 120 patients received droperidol 25 micrograms kg-1, metoclopramide 0.2 mg kg-1 or granisetron 40 micrograms kg-1 (n = 40 in each group) i.v. immediately before induction of anaesthesia. A standard general anaesthetic technique and postoperative analgesia were used throughout. There was a complete response, defined as no PONV and no administration of rescue medication, during the 24-h observation period in 45% of patients in the droperidol group, 38% in the metoclopramide group and 70% in the granisetron group (P = 0.021 vs droperidol, P = 0.003 vs metoclopramide). There was no difference in the incidence of adverse events between groups. We conclude that the prophylactic antiemetic efficacy of granisetron was superior to that of droperidol or metoclopramide for prevention of PONV in women during menstruation.      

Preoperative oral granisetron for the prevention of postoperative nausea and vomiting after breast surgery.

OBJECTIVE: To evaluate the efficacy and safety of oral granisetron for the prevention of postoperative nausea and vomiting after breast surgery. DESIGN: Prospective, randomised, double-blind, placebo-controlled study. SETTING: University affiliated hospital, Japan. SUBJECTS: 100 women listed for partial or modified radical mastectomy with or without axillary dissection. INTERVENTIONS: Patients were given either placebo or granisetron in three different doses (1 mg, 2 mg, 4 mg) orally 1 hour preoperatively (n = 25 in each group). A standard general anaesthetic technique and postoperative analgesia were used. MAIN OUTCOME MEASURES: All episodes of nausea and vomiting during the first 24 hours after anaesthesia. RESULTS: Complete response, defined as no nausea and vomiting and no need for a "rescue" antiemetic, during the first 24 hours after anaesthesia was recorded in 13 (52%) with placebo, 14 (56%) with granisetron 1 mg, 22 (88%) with 2 mg, and 22 (88%) with 4 mg, respectively (p = 0.006, Fisher's exact test). No clinically serious adverse events were seen in any of the groups. CONCLUSION: Preoperative oral granisetron, in doses of more than 2 mg, is effective for the prevention of postoperative nausea and vomiting in women undergoing general anaesthesia for breast surgery.     

The effectiveness of rescue antiemetics after failure of prophylaxis with ondansetron or droperidol: a preliminary report

STUDY OBJECTIVES: To compare the effectiveness of treating established postoperative nausea and vomiting (PONV) with an antiemetic acting at a different receptor with that of treating PONV with the antiemetic used for prophylaxis. DESIGN: Analysis of data collected in a previously published randomized, double-blind, placebo-controlled study. SETTING: Outpatient surgical procedures from 50 institutions in North America. PATIENTS: Patients (N = 2061) undergoing outpatient surgical procedures planned to last no more than 2 hours. INTERVENTIONS: Patients were randomized to receive ondansetron 4 mg, droperidol 1.25, droperidol 0.625 mg, or placebo. In the postoperative anesthesia care unit, patients who developed PONV received rescue antiemetics at the discretion of the attending anesthesiologist. The following antiemetics were used for rescue: ondansetron 4 mg, droperidol 0.625 to 1.25 mg, metoclopramide 10 mg, promethazine 6.25 to 25 mg, and dimenhydrinate 25 to 50 mg. MEASUREMENTS: The complete response rate (no nausea, no emesis, and no need for further rescue) after administration of the rescue antiemetic in patients with established PONV was calculated. The complete response rate after administration of each of the different rescue antiemetics was compared with that after administration of the same antiemetic used for PONV prophylaxis. MAIN RESULTS: In patients who failed prophylaxis with ondansetron 4 mg, the complete response rate was significantly higher (P = .02) after rescue with promethazine 6.25 to 25 mg (78%) than after rescue with ondansetron 4 mg (46%). In patients who failed prophylaxis with droperidol 0.625 and 1.25 mg, the complete response rate was significantly higher after rescue with promethazine 6.25 to 25 mg (77%; P = .02) and dimenhydrinate 25 to 50 mg (78%; P = .04) than after rescue with droperidol 0.625 to 1.25 mg (56%). CONCLUSION: In patients who failed prophylaxis with ondansetron or droperidol, promethazine was significantly more effective than the agent used for prophylaxis for the treatment of PONV. In patients who failed prophylaxis with droperidol, dimenhydrinate was also more effective than droperidol for the treatment of established PONV in the postoperative anesthesia care unit.