Objectives: This is an evaluation of the efficacy of metoclopramide (MTCP) or diphenhydramine (DPH) to relieve symptoms of motion sickness in patients being transported via ambulance in a mountainous setting.

Methods: This is a prospective, randomized, double-blinded, placebo-controlled study of patients transported by ambulance in the Sierra Nevada mountains of Fresno County. Consenting patients who met the inclusion criteria were asked to rate their motion sickness every five minutes using a visual analog scale (VAS) during transport. If motion sickness occurred, they were randomized to receive MTCP (20 mg IV), DPH (50 mg IV), or placebo (normal saline), and remaining symptoms were recorded every five minutes. If signs and symptoms of motion sickness persisted after 15 minutes, a rescue dose of MTCP was offered.

Results: Twenty-six patients were enrolled in the study. Twenty-two (84.6%) developed motion sickness and were randomized to MTCP, DPH, or placebo. Eight patients received MTCP, seven received DPH, and seven received placebo. The MTCP group showed a statistically significant decrease in the mean VAS score at 15 minutes compared to the DPH and placebo groups. There was no significant difference in the decrease in VAS score between the placebo and the DPH group. Twelve out of 22 patients requested a rescue dose of MTCP after 15 minutes. At 25 minutes, there was no significant difference in the VAS score between the three groups.

Conclusion: During ambulance transport in a mountainous setting, the administration of MTCP is superior to both DPH and placebo in the treatment of motion sickness. Diphenhydramine is not superior to placebo.

Summary

Background and objective: Metoclopramide is an antiemetic drug which inhibits plasma cholinesterase activity. We have compared the mivacurium infusion requirements and neuromuscular recovery after administration of metoclopramide to a group of adults compared to a control group.

Methods: Forty-five patients were randomized into three groups. Two groups received either 10 or 20 mg of intravenous (i.v.) metoclopramide and the third group received i.v. saline. Metoclopramide and saline were given 5 min before i.v. induction of anaesthesia. Plasma cholinesterase activity was measured before induction and 30 min after metoclopramide or saline injection. Neuromuscular block was monitored by accelerography using single and train-of-four (TOF) stimulation. The mivacurium intubation dose was followed by an infusion titrated every 5 min to maintain 95% block until the end of surgery when the infusion was stopped. Recovery from mivacurium was then monitored until complete.

Results: Mivacurium infusion rates were significantly lower in the metoclopramide groups. After 45 min of infusion, the infusion rates were 1.82 ± 0.8 and 2.1 ± 1 μg kg−1 min−1 in the 20 and 10 mg metoclopramide groups, respectively, and 6.8 ± 2.7 in the saline group. Time to recovery of TOF to greater than 90% was significantly prolonged in both metoclopramide groups compared to the saline group: 33.2 ± 7.2 and 29.5 ± 10.3 min in the metoclopramide 20 and 10 mg groups, respectively, compared to 22 ± 3.9 in the saline group (P < 0.001 for the 20 mg group compared to control).

Conclusion: Metoclopramide enhances the effect of a mivacurium infusion.

Background and objective Female patients undergoing gynaecological procedures, especially laparoscopically, are at high risk of postoperative nausea and vomiting. No available antiemetic is entirely effective. This double-blinded randomized trial examines the efficacy and safety of tropisetron and metoclopramide in combination and compares the results with metoclopramide alone in laparoscopic gynaecological surgery.

Methods One hundred and twenty female patients scheduled for minor gynaecological laparoscopy, aged 27–43 years, were randomly allocated to receive pretreatment with metoclopramide 10 mg intravenously (n = 57) or tropisetron 5 mg with metoclopramide 5 mg (n = 63).

Results Fewer patients in the combined treatment group experienced postoperative nausea and vomiting (14% vs. 37%, P = 0.008) or needed rescue antiemetic treatment (3% vs. 16%, P = 0.038). No significant adverse events were observed.

Conclusions The combination of the antiemetics was superior, which is probably explained by the fact that the two drugs have different sites of action, thus preventing emesis by blocking different pathways.

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 metoclo-pramide-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.

Nausea and vomiting are common side effects of opioids administered for pain control. This double-blind, randomized, parallel-group study evaluated the anti-emetic efficacy and tolerability of single intravenous (i.v.) doses of ondansetron 8 mg, ondansetron 16 mg and metoclopramide 10 mg in the treatment of opioid-induced emesis. Adult patients undergoing low emetogenic surgical procedures, using a standardized anaesthesia regimen were assessed for 24 h following administration of study anti-emetic to treat established post-surgical opioid-induced emesis. A total of 4511 patients were enrolled of whom 1366 experienced opioid-induced emesis and received randomized study medication. Ondansetron 8 mg and 16 mg were significantly better than metoclopramide 10 mg (P < 0.05) for both complete control of emesis, complete control of nausea and other efficacy measures. There were no significant differences between the two ondansetron groups. All three treatments were well tolerated. In conclusion, this large, multicentre study demonstrates that ondansetron is more effective than metoclopramide in the treatment of opioid-induced emesis following administration of post-surgical opioids to control pain.

This study evaluates the prophylactic anti-emetic efficacy of granisetron, droperidol and metoclopramide, for the prevention of post-operative nausea and vomiting in female patients undergoing elective laparoscopic cholecystectomy. The patients were randomly assigned to one of four groups (n=30 for each group): granisetron 3 mg, droperidol 1.25 mg, metoclopramide 10 mg and placebo (saline). These medications were given immediately before the induction of anaesthesia. During the first 24 h after an-aesthesia, the incidence of post-operative nausea and vomiting was 13, 30, 33 and 37% after administration of granisetron, droperidol, metoclopramide and placebo, respectively (P>0.05, overall Fisher's exact probability test). No clinically important adverse effects were observed in either group. Our results suggest that granisetron is a better anti-emetic than droperidol or metoclopramide for the prevention of post-operative nausea and vomiting after laparoscopic cholecystectomy when compared with a placebo.

Ondansetron 4 mg was compared with metoclopramide 10 mg for prevention of post-operative nausea and emesis in in-patients undergoing major gynaecological surgery in this double-blind, randomized, placebo-controlled, multicentre study. A total of 1044 patients received a single intravenous (i.v.) injection of study medication immediately before induction of anaesthesia. Nausea and emesis were assessed over the 24 h post-operative period. Significantly more patients who received ondansetron experienced no emetic episodes (44%) compared with those who received metoclopramide (37%, P=0.049) or placebo (25%, P<0.001). No nausea was experienced by significantly more patients who received ondansetron (32%) than with patients who received metoclopramide (24%, P=0.009) or placebo (16%, P<0.001). In addition, fewer emetic episodes, less severe nausea and a reduced need for rescue antiemetics were also observed with ondansetron (P<0.05 vs. metoclopramide and placebo). Metoclopramide and placebo-treated patients were also 1.5 times (95% CI 1.5–4.2) and 2.5 times (95% CI 1.1–2.0) more likely, respectively, to experience nausea post-operatively. Overall, ondansetron was the most effective antiemetic in this patient population.

Peri-operative nausea and vomiting (PONV), remain a considerable problem. Ondansetron is being promoted currently as the drug of choice for the prevention and treatment of PONV. Experiments to investigate efficacy of ondansetron in PONV have been made with placebo or single doses of other drugs, e.g. metoclopramide, and often with different anaesthetic regimes with different emetic potential. This study investigated the relative benefits, in the prevention of PONV, of ondansetron compared with metoclopramide used at a dose higher than used in previous studies. Ninety-six patients undergoing minor gynaecological surgery were randomized to receive either ondansetron 4 mg or metoclopramide 0.4 mg kg−1. The patients were then assessed in the recovery room, in the day ward prior to discharge and the following day for the occurrence of PONV. Emetic symptoms occurred in similar proportions of patients who received ondansetron and metoclopramide. Nausea scores were similar between the groups in the recovery ward and 24-h follow-ups but there were higher post-operative nausea scores in the ondansetron group in the day ward (P = 0.001). There were no significant side effects due to either drug. We conclude that moderate dose metoclopramide is an effective alternative to ondansetron in the control of PONV.

Nausea and vomiting remain unpleasant side effects of intrathecal (i.t.) morphine and of the numerous therapies tried, only prophylactic intravenous (i.v.) metoclopramide has been reported to be promising. Seventy-three patients, scheduled for orthopaedic prosthesis surgery of the hip or knee were studied. They received 4mL of plain bupivacaine and 0.3 mg of preservative-free morphine i.t. for anaesthesia. The test drugs given in a double-blind and randomized fashion, were either metoclopramide 20 mg, three times, at 6 h intervals (23 patients), ondansetron, 8 mg, twice, at 12 h intervals (25 patients), or 0.9% saline three times, at 6 h intervals (25 patients). The occurrence of nausea, vomiting and pain was followed for 24 h. The incidences of nausea and vomiting were 60% (15/l25) and 56% (14/25) in the saline group, 52% (12/23) and 48% (11/23) in the metoclopramide group, and 52% (13/25) and 40% (10/25) in the ondansetron group. Incidences of severe vomiting were 24, 35 and 12%, respectively. Eight patients in the saline group, seven in the metoclopramide and 10 in the ondansetron group did not need additional opioids for post-operative pain relief. We conclude that, metoclopramide and ondansetron were not better than saline in the prevention of post-operative emesis induced by intrathecal morphine.

The efficacy of ondansetron 4 mg was compared with metoclopramide 10 mg for the prevention of post-operative nausea and vomiting in patients after major gynaecological abdominal surgery. Anaesthesia was standardized using thiopentone, atracurium and methadone for induction followed by isoflurane in nitrous oxide-oxygen mixture. Fifty patients were randomized in a double-blind fashion to either receive intravenous(i.v.) ondansetron 4 mg or metoclopramide 10 mg during closure of the pelvic peritoneum. The incidence and frequency of vomiting, and the incidence of severe nausea was recorded for 24 h after surgery. One patient was excluded because of respiratory depression. In the first 4 h after surgery, five patients (20%) in the ondansetron group (n = 25) and eight patients (33%) in the metoclopramide group (n = 24) vomited, whereas at 4–12 h, this increased to 11 patients (44%) and nine patients (37.5%) respectively. The incidence was 52 and 37.5% respectively in the subsequent 12–24 h. The highest incidence of nausea was in the first 4 h after surgery, being 56 and 37.5% in the ondansetron and the metoclopramide groups respectively. This decreased to less than 25% in both groups in the 12–24 h period. Ondansetron 4 mg and metoclopramide 10 mg had similar but short lasting efficacy for the prevention of vomiting in patients who received continued opioid analgesia after major gynaecological surgery.