Effects of propofol on ipecacuanha-induced nausea and vomiting

Background : The purpose of this study was to evaluate if propofol has 5-HT₃ antagonistic effects. Ipecacuanha is known to release serotonin (5-HT) in the gastrointestinal tract and therefore ipecacuanha syrup was used to induce nausea and vomiting. The 5-HT₃ antagonist ondansetron was used as a control substance.
Results : During the first 150 min after ingestion of ipecacuanha there were no retchings during the ondansetron infusion ( P = 0.01 vs placebo, P =0.02 vs propofol) and significantly fewer retchings during propofol infusion compared to placebo ( P <0.02). There was no nausea during the ondansetron infusion ( P <0.01 vs placebo and propofol) but the volunteers experienced nausea both during the placebo and propofol infusion (NS).
Conclusion : This study in volunteers has shown that propofol reduces the intensity of retching after oral intake of ipecacuanha syrup. As ipecacuanha releases 5-hydroxytryptamine, it can be concluded that propofol may have a weak 5-HT₃ antagonistic effect.
Method : Ten healthy male volunteers (20–37 years) were studied on three occasions and were randomly allocated to receive a concomitant infusion of propofol (initial bolus 0.1 mg kg^-1 then 1 mg kg^-1h^-1), ondansetron (initial bolus 0.11 mg kg^-1 then 14 μg kg^-1 h^-1) and placebo on either occasion. The infusions started 30 min before oral ingestion of 30 ml of ipecacuanha and continued until 150 min after the intake. The number of retchings was recorded and the intensity of nausea was estimated by the subjects on a visual analog scale.     

Betamethasone does not prevent nausea and vomiting induced by the dopamine-agonist apomorphine

PURPOSE: The mechanism of the antiemetic actions of corticosteroids is not known. The purpose of this study was to evaluate if betamethasone can prevent nausea, vomiting or increase of vasopressin induced by apomorphine. Metoclopramide, a dopamine antagonist, was used as a control substance. METHODS: Ten healthy volunteers were studied on three occasions. In a randomized order they were allocated to receive pretreatment with betamethasone 8 mg iv, metoclopramide 10 mg iv, and normal saline 2 mL as placebo on the three different occasions, 15 min before the administration of apomorphine 30 microg x kg(-1) s.c.. After administration of apomorphine, episodes of vomiting were recorded, and the intensity of nausea was estimated by the subject on a visual analogue scale (VAS 0-10 cm). Blood samples for analysis of plasma concentrations of vasopressin were analyzed. RESULTS: One volunteer decided to withdraw, as he experienced akathisia after receiving metoclopramide. During the first two hours after apomorphine, eight of nine volunteers vomited both after betamethasone and placebo. One volunteer did not vomit after betamethasone and placebo but he experienced nausea. None of the volunteers vomited after metoclopramide (P < 0.01 vs betamethasone and placebo). The maximum VAS for nausea was significantly higher after betamethasone and placebo compared to metoclopramide (P < 0.01). The vasopressin levels increased after betamethasone and placebo, but there was no increase in any volunteer after pretreatment with metoclopramide. CONCLUSION: This study demonstrates that betamethasone does not prevent nausea, vomiting and increase of vasopressin induced by apomorphine, whereas metoclopramide prevents apomorphine-induced emesis. Our work suggests that betamethasone does not have dopamine-antagonistic effects.     

Ondansetron versus droperidol or placebo to prevent nausea and vomiting after otologic surgery

This study compares the preoperative administration of ondansetron with that of droperidol or saline solution for the prevention of nausea and vomiting in otologic surgery patients. A total of 120 otherwise healthy individuals were randomly assigned to receive either saline solution, ondansetron (4 mg intravenously), or droperidol (25 μg/kg intravenously) before anesthetic induction. Intraoperative and postanesthesia care unit times were recorded along with incidence of nausea, vomiting, pain, nausea and recovery scores, and the administration of rescue antiemetics. Similar assessments were made during the next 24 hours. Demographics were similar, but more males received ondansetron. Anesthetic recovery scores were lower after administration of droperidol than after ondansetron. Incidence of nausea was similar between groups, but severity was greater with placebo and droperidol than with ondansetron. More vomiting occurred with placebo than with ondansetron or droperidol. No intergroup differences in rescue antiemetic administration were noted, however. Twenty-four hours later, more patients receiving placebo had nausea or vomited than patients receiving droperidol or ondansetron. Fewer women in the ondansetron group vomited than in the other two groups. Ondansetron 4 mg intravenously is as effective as droperidol and better than saline solution in preventing nausea and vomiting in patients undergoing otologic surgery. No cost advantage as determined by lower use of rescue antiemetics or shorter postanesthesia care unit times was noted after ondansetron therapy. (Otolaryngol Head Neck Surg 1998;118:785-9.)     

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.     

Treatment of postoperative nausea and vomiting with ondansetron: a randomized, double-blind comparison with placebo

Postoperative nausea and vomiting are common after recovery from general anesthesia. The antiemetic effect and safety of ondansetron, a selective serotonin type 3 (5-HT3) receptor antagonist, was determined in 36 patients suffering from nausea or vomiting during recovery from intravenous anesthesia by giving either a single intravenous dose of ondansetron (8 mg, n = 18) or placebo (n = 18) over 2-5 min in a randomized, double-blind manner. A "rescue" antiemetic was provided in case of continued vomiting or at the patient's request. Antiemetic efficacy was defined as no request for rescue antiemetic and/or no vomiting episode during the next 4 h. There was no significant difference in the demographic data between the groups. Administration of ondansetron or placebo had no significant effect on vital signs. Ondansetron was an effective antiemetic in 78% (14/18) and placebo was effective in 28% (5/18) of the patients. Laboratory studies 24 h later showed no signs of hematologic, hepatic, or renal alterations. Ondansetron at a dose of 8 mg administered intravenously over 2-5 min appears to be a safe and effective antiemetic for the treatment of nausea and/or vomiting after intravenous anesthesia.     

Prevention of postoperative nausea and vomiting using ondansetron, a new, selective, 5-HT3 receptor antagonist.

The effect of ondansetron, a 5-HT3 antagonist, in preventing postoperative nausea and vomiting was investigated in a randomized, double-blind, placebo-controlled study of 84 patients undergoing gynecologic operation and receiving the same general anesthetic. The patients received premedication with either 16 mg oral ondansetron, or a matching placebo. The same medication was given postoperatively 8 h after the first dose. During the first hour after recovery from anesthesia, the frequencies of nausea and vomiting were 52% and 40%, respectively, in patients given placebos. In the ondansetron group nausea and vomiting developed in 17% and 12%, respectively, values significantly different from those with placebos (P less than 0.005). Similar differences were observed throughout the entire 24-h period after recovery, the incidence of nausea and vomiting being 67% and 60%, respectively, in the placebo group and 29% and 26% in the ondansetron treatment group. Ondansetron appears to be a promising antiemetic for the prevention of postoperative nausea and vomiting.     

Ondansetron for treatment of intrathecal morphine-induced pruritus after cesarean delivery

BACKGROUND AND OBJECTIVES: Pruritus induced by intrathecal morphine is a concern in many obstetric patients after cesarean delivery and may detract from the benefit of postoperative pain relief. This study was performed to investigate the efficacy of ondansetron (5-HT3 receptor antagonist) in treatment of pruritus following intrathecal morphine. METHODS: Eighty parturients developing moderate to severe pruritus following intrathecal morphine were randomly allocated into 2 groups. One group received 4 mg ondansetron while the other group received placebo (normal saline). The improvement of pruritus and other adverse effects such as pain scores, nausea, vomiting, sedation, hallucination, and respiratory depression were determined at 30 minutes after study drugs' administration. RESULTS: The treatment success rate was higher in the ondansetron group than in the placebo group (80% v 36%, P < .001). Among the successfully treated patients, the recurrence rates of moderate to severe pruritus within 4 hours after administration of ondansetron and placebo were 12% and 70%, respectively (P < .001). The number of patients with decreased nausea and vomiting score was also higher in the ondansetron group (11 v 1, P < .006). CONCLUSION: Ondansetron treats intrathecal morphine-induced pruritus after cesarean delivery, particularly in patients suffering from both nausea/vomiting and pruritus.     

Tropisetron vs ondansetron for prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy: a randomized double-blind,placebo-controlled study

Background: Postoperative nausea and vomiting are observed in increased frequency after laparoscopic surgery. This study was performed in order to compare the efficacy of two 5-hydroxytryptamine-3 (5-HT3) receptor antagonists, ondansetron and tropisetron, in preventing postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy. Methods: Using a randomized, double-blind study design, 87 ASA I and II patients scheduled for laparoscopic cholecystectomy were randomly assigned to receive 4 mg ondansetron (Group A, n = 29), 5 mg tropisetron (Group B, n = 31), or placebo (Group C, n = 27) intravenously (IV) before induction of anesthesia. The end points evaluated were frequency of nausea, nausea intensity rated on a scale from 1 (mild) to 5 (most severe), frequency of vomiting, and need for rescue antiemetics. These parameters were measured immediately after surgery (0 h), at 3 h, 6 h, and 12 h postoperatively. Results: The frequency of nausea was significantly higher in group A (31.2%) compared to group B (14%) at 12 h postoperatively (p <0.01). However, patients of group A had significantly lower nausea scores at 3 h postoperatively compared to group B. Postoperative vomiting occurred in 13.8% of patients in group A and 9.6% of patients in group B throughout the whole study period (p = n.s.). The need for rescue antiemetics was similar between groups A and B. Both groups were superior to placebo concerning all studied parameters. Conclusion: Our results show that ondansetron may be more effective in controlling nausea intensity during the first 3 h after laparoscopic cholecystectomy, while tropisetron has a longer-acting activity, with a major impact on nausea frequency at 12 h postoperatively.     

Prevention of postoperative nausea and vomiting by ondansetron]

This study was carried out to assess the efficacy of oral ondansetron, a new 5HT3 receptor antagonist, in patients undergoing thyroid surgery. It included 60 patients, randomly assigned to two groups, and receiving orally, 1 h before induction of anaesthesia, either 8 mg of ondansetron (n = 29) or a placebo (n = 30). One patient was excluded. The same anaesthetic protocol, consisting of 3 to 5 micrograms.kg-1 of fentanyl, 4 to 6 mg.kg-1 of thiopentone, and 0.5 mg.kg-1 of atracurium, was used in all. Anaesthesia was maintained with 50% nitrous oxide in oxygen with 0.8 to 1% endtidal concentration of isoflurane and additional boluses of 0.1 mg of fentanyl as required. The incidence and intensity of nausea, graded mild, moderate or severe, and the incidence of vomiting were recorded postoperatively. During the first twelve hours after surgery, 40% of patients in the placebo group had nausea (16.7% mild, 20% moderate and 6.7% severe), and 50% vomited. In the ondansetron group, nausea and vomiting occurred in 13.8% and 20.4% of patients respectively. The 4 patients in the latter group complained of major nausea. The differences between the groups were statistically significant: p = 0.025 for nausea and p = 0.042 for vomiting. It is concluded that oral ondansetron, 8 mg taken orally 1 h before surgery, significantly reduces the incidence of nausea and vomiting during the first twelve postoperative hours. As it is easy to use and has no side-effects, it might be of interest in day-case surgery patients, despite its high cost.     

Intravenous dolasetron and ondansetron in prevention of postoperative nausea and vomiting: a multicenter, double-blind, placebo-controlled study

Background: Intravenous dolasetron mesilate has shown efficacy in the prevention of postoperative nausea and vomiting (PONV) when administered as a single dose prior to emergence from anesthesia. This trial compared intravenous dolasetron and ondansetron for the prevention of PONV when administered at induction of anesthesia.
Methods: This double-blind, placebo-controlled, multicenter trial randomized patients to one of four single IV treatments: placebo, 25 or 50 mg dolasetron, or 4 mg ondansetron. Efficacy was measured by complete response (0 emetic episodes and no rescue medication), nausea severity and patient satisfaction as measured on a visual analog scale (VAS), investigator's rating of nausea severity, and total response (complete response with no nausea [≤ mm VAS]).
Results: 514 patients at 24 sites were evaluated for efficacy. The 50 mg dolasetron and 4 mg ondansetron doses were statistically equivalent, and superior to placebo, for all efficacy measures. Complete response rates were 49%, 51%, 71% and 64% for placebo, 25 and 50 mg dolasetron, and ondansetron, respectively. Dolasetron 50 mg was statistically superior to 25 mg dolasetron for complete response, total response, VAS maximum nausea, time to first emetic episode, and patient satisfaction. The majority of adverse events were of mild-to-moderate intensity. Headache was the most frequently reported treatment-related adverse event with a 3%-5% incidence across treatments.
Conclusion: When given at induction of anesthesia, 50 mg intravenous dolasetron is equivalent to 4 mg ondansetron and superior to 25 mg dolasetron and placebo for the prevention of PONV. All treatments were safely administered and well tolerated.     

Effect and placebo effect of acupressure (P6) on nausea and vomiting after outpatient gynaecological surgery

BACKGROUND: Acupuncture and acupressure have previously been reported to possess antiemetic effect. We wanted to investigate the "true" and placebo effect of acupressure in prevention of postoperative nausea and vomiting (PONV). PATIENTS AND METHODS: Sixty women undergoing outpatient minor gynaecological surgery were entered into a double-blind and randomised study. One group received acupressure with bilateral stimulation of P6 (A), a second group received bilateral placebo stimulation (P) and a third group received no acupressure wrist band and served as a reference group (R). PONV was evaluated as number of patients with complete response (no PONV), nausea only or vomiting. In addition, the need for rescue antiemetic medication and nausea after 24 h was registered. RESULTS: Complete response was obtained in 11, 11 and 9 patients in groups, A, P and R, respectively. Nine, 7 and 6 patients had nausea before discharge home, and 1, 1 and 8 patients were nauseated (8 vs 1 patient: P < 0.05) 24 h after operation in A, P and R groups, respectively. When compared to placebo acupressure (2 patients vomited and 5 needed rescue), significantly (P < 0.05) fewer needed rescue antiemetic medication after acupressure at P6 (no vomiting or rescue medication). When compared to the observation group (5 vomited and 4 needed rescue antiemetics), significantly fewer vomited after acupressure (P < 0.05) CONCLUSION: In patients undergoing brief gynaecological surgery, placebo effect of acupressure decreased nausea after 24 h but vomiting and need of rescue antiemetics was reduced only by acupressure with the correct P6 point stimulation.     

Prophylactic ondansetron is effective in the treatment of nausea and vomiting but not on pruritus after cesarean delivery with intrathecal sufentanil-morphine

STUDY OBJECTIVES: To assess the safety and efficacy of ondansetron for prevention of pruritus, nausea and vomiting after cesarean delivery with intrathecal sufentanil-morphine. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Referral center, institutional practice. PATIENTS: 100 nonbreastfeeding women undergoing elective cesarean delivery with sufentanil-morphine-bupivacaine anesthesia. INTERVENTIONS: After the umbilical cord was clamped, patients in Group 1 received ondansetron 8 mg intravenously (IV) and patients in Group 2 received placebo. MEASUREMENTS: Frequency and severity of postoperative (24-hour) pruritus, nausea and vomiting, surgical pain, and side effects related to ondansetron were recorded. MAIN RESULTS: In the ondansetron group, 38 patients had pruritus (16 mild and 22 severe) and 9 patients had nausea and vomiting (5 mild and 4 severe). In the placebo group, 41 patients had pruritus (21 mild and 20 severe) and 29 patients had nausea and vomiting (9 mild and 15 severe). The frequency and severity of the nausea and vomiting episodes were significantly reduced in the ondansetron group. Pain scores were comparable between groups. No side effects related to ondansetron were reported. CONCLUSIONS: Prophylactic IV ondansetron 8 mg is safe and effective in reducing the frequency and the severity of nausea and vomiting, but not pruritus, following cesarean delivery with intrathecal sufentanil-morphine.     

Efficacy, Dose-Response, and Safety of Ondansetron in Prevention of Postoperative Nausea and Vomiting: A Quantitative Systematic Review of Randomized Placebo-controlled Trials

Objective: The authors reviewed efficacy and safety data for ondansetron for preventing postoperative nausea and vomiting (PONV).

Methods: Systematically searched, randomized, controlled trials (obtained through MEDLINE, EMBASE, Biological Abstracts, manufacturer's database, manual searching of journals, and article reference lists) were analyzed. Relevant end points were prevention of early PONV (within 6 h after surgery) and late PONV (within 48 h) and adverse effects. Relative benefit and number-needed-to-treat were calculated. The number-needed-to-treat indicated how many patients had to be exposed to ondansetron to prevent PONV in one of them who would have vomited or been nauseated had he or she received placebo.

Results: Fifty-three trials were found that had data from 7,177 patients receiving 24 different ondansetron regimens and from 5,712 controls receiving placebo or no treatment. Average early and late PONV incidences without ondansetron were 40% and 60%, respectively. There was a dose response for oral and intravenous ondansetron. Best number-needed-to-treat to prevent PONV with the best documented regimens was between 5 and 6. This was achieved with an intravenous dose of 8 mg and an oral dose of 16 mg. Antivomiting efficacy was consistently better than antinausea efficacy. Efficacy in children was poorly documented. Ondansetron significantly increased the risk for elevated liver enzymes (number-needed-to-harm was 31) and headache (number-needed-to-harm was 36).     

Erbrechen nach gynäkologischen Laparoskopien in Allgemeinanästhesie ist assoziiert mit Veränderungen der Serotoninmetabolitenausscheidung

INTRODUCTION: The efficacy of 5-HT(3)-receptor antagonists suggests a role of serotonin in the pathogenesis of postoperative nausea and vomiting (PONV). However, studies investigating the relationship between the turnover of serotonin and PONV were contradictory. Therefore we carried out a pilot study in order to find out whether results can be obtained that would justify further studies on a larger scale. METHODS: A total of 22 patients scheduled for elective gynaecological laparoscopy were enrolled. A balanced anaesthesia using sufentanil, etomidate, cisatracurium, isoflurane and nitrous oxide was administered and 5-hydroxyindoleaceticacid (5-HIAA) concentrations in the urine were measured within the 24 h after surgery. RESULTS: Only the patients that vomited postoperatively had a significant change in the concentrations of 5-HIAA over the time course investigated. However, comparison of urinary 5-HIAA concentrations of the group comprising patients that vomited with those that had no PONV did not reveal a significant difference. CONCLUSIONS: Results of this study support further investigation of the relationship between serotonin and PONV and suggest that there may in fact be an association between PONV and increased serotonin turnover.     

Comparison of oral dolasetron and ondansetron in the prophylaxis of postoperative nausea and vomiting in children

BACKGROUND AND OBJECTIVE: In a randomized, placebo-controlled, double-blind trial, we compared the efficacy of oral dolasetron and ondansetron in preventing postoperative nausea and vomiting in children after various surgical operations. METHODS: Children were assigned randomly to one of three groups (each contained 50 children) to receive dolasetron 1.8 mg kg(-1) or ondansetron 0.15 mg kg(-1) orally, or a placebo. All children received methylene blue capsules (10 mg) orally as an indicator before the induction of anaesthesia. Postoperatively, contamination of the mouth and the endotracheal tube by methylene blue was recorded, and postoperative nausea and vomiting was recorded for 0-1, 1-24 and 0-24 h. Metoclopramide (0.1 mg kg(-1)) intravenously was used as the rescue antiemetic. RESULTS: In the 0-1 h period after operation, there were no differences between the groups. In the 1-24 h period, dolasetron was significantly better than placebo (nausea 8 versus 24%; vomiting 4 versus 20%; total nausea and vomiting scores 16 versus 48%). Over the 0-24 h period, both dolasetron and ondansetron were significantly better than placebo (nausea 16 versus 26 versus 40%), vomiting (8 versus 16 versus 30%), and total nausea and vomiting scores (32 versus 48 versus 78%). There were no significant differences between dolasetron and ondansetron. There was no important methylene blue contamination, and little use of rescue metoclopramide. There were no important adverse events. CONCLUSIONS: Prophylactic oral dolasetron and ondansetron were effective in reducing postoperative nausea and vomiting in children.     

Effect of prophylactic ondansetron on postoperative nausea and vomiting after elective craniotomy.

This prospective, randomized, placebo-controlled, double-blind study was designed to evaluate the efficacy of ondansetron, a 5-HT3 antagonist, in preventing postoperative nausea and vomiting (PONV) after elective craniotomy in adult patients. The authors also tried to discover certain predictors for postcraniotomy nausea and vomiting. We studied 170 ASA physical status I and II patients, aged 15 to 70 years, undergoing elective craniotomy for resecting various intracranial tumors and vascular lesions. A standardized anesthesia technique and postoperative analgesia were used for all patients. Patients were divided into two groups and received either saline placebo (Group 1) or ondansetron 4 mg (Group 2) intravenously at the time of dural closure. Patients were extubated at the end of surgery and episodes of nausea and vomiting were noted for 24 hours postoperatively in the neurosurgical intensive care unit. Demographic data, duration of surgery, and anesthesia and analgesic requirements were comparable in both groups. Overall, a 24-hour incidence of postoperative emesis was significantly reduced in patients who received ondansetron compared with those who received a saline placebo (39% in Group 1 and 11% in Group 2, P = .001). There was a significant reduction in the frequency of emetic episodes and rescue antiemetic requirement in patients treated with ondansetron; however, ondansetron did not significantly reduce the incidence of nausea alone (14% in Group 2 vs 5% in Group 1, P = .065). Prophylactic ondansetron had a favorable influence on PONV outcome measures such as patient satisfaction and number needed to prevent emesis (3.5). Side effects were similar in both groups. We conclude that ondansetron 4 mg given at the time of dural closure is safe and effective in preventing emetic episodes after elective craniotomy in adult patients.     

Dexamethasone for the prevention of postoperative nausea and vomiting: a quantitative systematic review

The role of dexamethasone in the prevention of postoperative nausea and vomiting (PONV) is unclear. We reviewed efficacy and safety data of dexamethasone for prevention of PONV. A systematic search (MEDLINE, EMBASE, Cochrane Library, hand searching, bibliographies, all languages, up to April 1999) was done for full reports of randomized comparisons of dexamethasone with other antiemetics or placebo in surgical patients. Relevant end points were prevention of early PONV (0 to 6 h postoperatively), late PONV (0 to 24 h), and adverse effects. Data from 1,946 patients from 17 trials were analyzed: 598 received dexamethasone; 582 received ondansetron, granisetron, droperidol, metoclopramide, or perphenazine; 423 received a placebo; and 343 received a combination of dexamethasone with ondansetron or granisetron. With placebo, the incidence of early and late PONV was 35% and 50%, respectively. Sixteen different regimens of dexamethasone were tested, most frequently, 8 or 10 mg IV in adults, and 1 or 1.5 mg/kg IV in children. With these doses, the number needed to treat to prevent early and late vomiting compared with placebo in adults and children was 7.1 (95% CI 4.5 to 18), and 3.8 (2.9 to 5), respectively. In adults, the number needed to treat to prevent late nausea was 4.3 (2.3 to 26). The combination of dexamethasone with ondansetron or granisetron further decreased the risk of PONV; the number needed to treat to prevent late nausea and vomiting with the combined regimen compared with the 5-HT3 receptor antagonists alone was 7.7 (4.8 to 19) and 7.8 (4.1 to 66), respectively. There was a lack of data from comparisons with other antiemetics for sensible conclusions. There were no reports on dexamethasone-related adverse effects. IMPLICATIONS: When there is a high risk of postoperative nausea and vomiting, a single prophylactic dose of dexamethasone is antiemetic compared with placebo, without evidence of any clinically relevant toxicity in otherwise healthy patients. Late efficacy seems to be most pronounced. It is very likely that the best prophylaxis of postoperative nausea and vomiting currently available is achieved by combining dexamethasone with a 5-HT3 receptor antagonist. Optimal doses of this combination need to be identified.     

Atrial fibrillation after ondansetron for the prevention and treatment of postoperative nausea and vomiting: a case report

PURPOSE: Even though clinical safety has been established in large studies, ondansetron has been reported to cause adverse cardiovascular events. We present a case of atrial fibrillation in association with ondansetron in the postoperative period. CLINICAL FEATURES: A 47-yr-old, 81 kg female presented with a benign lump in her left breast for lumpectomy. Her past medical history was unremarkable. Physically she was very active, non-smoker and had no allergies. She underwent the procedure under general anesthesia. She received 4 mg of ondansetron intravenously for postoperative nausea and vomiting prophylaxis at the end of the procedure and an additional 4 mg in the recovery room for nausea. Within 15 min after the second dose she was noted to be in atrial fibrillation that required admission to the hospital and procainamide infusion for conversion to normal sinus rhythm. She did not have any evidence of myocardial ischemia, valvular abnormality or pulmonary embolism. CONCLUSION: The 5-hydroxytryptamine 3 receptor (5-HT(3)) antagonist ondansetron has been reported to cause myocardial ischemia, supraventricular and ventricular tachycardia. Postulated mechanism includes inhibition of Bezold-Zarisch cardiac reflex and coronary vasoconstriction. Inhibition of 5-HT(3) receptors in the heart could lead to unopposed action of other serotonin receptors leading to atrial fibrillation or other tachyarrhythmias described in the literature.     

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.     

The Dose-Response Relationship of Ondansetron in Preventing Postoperative Emesis in Pediatric Patients Undergoing Ambulatory Surgery

Background: Postoperative nausea and vomiting is a distressing anesthetic complication that may delay discharge after ambulatory surgery. Effective prophylaxis for postoperative nausea and vomiting can be achieved in adults with lower doses of ondansetron, a 5-hydroxytryptamine subtype 3 receptor antagonist, compared with chemotherapy-induced emesis. However, the doses of ondansetron used in preventing postoperative nausea and vomiting in children are based on data from chemotherapy-induced emesis. The dose-related efficacy of intravenous ondansetron in the prophylaxis of postoperative emesis in the pediatric outpatient population was determined.

Methods: In a double-blind, randomized placebo-controlled study, 130 patients (mean age 5.7 plus/minus 3.4 yr) received placebo, 10, 50, or 100 micro gram/kg ondansetron during a standardized anesthetic. Episodes of postoperative vomiting or retching were recorded.

Results: Intravenous ondansetron in a dose of 50 micro gram/kg was more effective than placebo or a dose of 10 micro gram/kg in controlling the incidence and frequency of emesis in the hospital and during the first 24 postoperative hours. Increasing the dose of ondansetron to 100 micro gram/kg intravenously did not significantly reduce the incidence or frequency of emesis compared to 50 micro gram/kg intravenously.