Droperidol vs. prochlorperazine for benign headaches in the emergency department

OBJECTIVE

To compare the efficacy of droperidol with that of prochlorperazine for the treatment of benign headaches in emergency department (ED) patients.

METHODS

Prospective, randomized clinical trial in an urban ED. Patients were given either droperidol, 5 mg intramuscular (IM) or 2.5 mg intravenous (IV), or prochlorperazine, 10 mg IM or 10 mg IV. Measurements included side effects and the patient's pain perception as measured on a 100-mm visual analog scale (VAS) at baseline, 30, and 60 minutes after the medication was given. Data were analyzed using chi-square, two-tailed t-tests, and two-way analysis of variance (ANOVA) when appropriate.

RESULTS

During an eight-month period, 168 patients were enrolled. Eighty-two (48.8%) of the patients received droperidol; 86 (51.2%) received prochlorperazine. In the droperidol group, 49 (59.6%) received IM administration and 33 (40.4%) IV. In the prochlorperazine group, 57 (66.3%) received IM administration and 29 (33.7%) IV. Sixty minutes after the medication, the mean decrease in the VAS scores was 81.4% for droperidol and 66.9% for prochlorperazine (p = 0.001). At 30 minutes, 60.9% of the patients receiving droperidol and 44.2% of the patients receiving prochlorperazine had obtained at least a 50% reduction in their VAS scores (p = 0.09). At 60 minutes, 90.2% of the patients receiving droperidol and 68.6% of the patients receiving prochlorperazine had at least a 50% reduction in their VAS scores (p = 0.017). No difference between IM dosing and IV dosing was detected. Side effects, including dystonia, akathisia, and decreased level of consciousness, were seen in 15.2% of the patients receiving droperidol and 9.61% of the patients receiving prochlorperazine. No significant or persisting morbidity was detected.

CONCLUSIONS

Droperidol was more effective than prochlorperazine in relieving pain associated with benign headaches.

[Droperidol and dimenhydrinate alone or in combination for prevention of postoperative nausea and vomiting]

BACKGROUND

Droperidol and dimenhydrinate are inexpensive antiemetic drugs. Droperidol, especially, has been studied extensively in the past, but there are no studies that used the combination of both drugs for prevention of postoperative nausea and vomiting (PONV). Thus, the aim of this randomised controlled and double-blinded study was to evaluate the antiemetic efficacy and the side effects of such a combination therapy.

METHODS

240 inpatients undergoing ENT surgery under general anaesthesia were randomised to receive one of four antiemetic regimes: placebo, dimenhydrinate (1 mg x kg-1), droperidol (15 micrograms x kg-1), or the combination of both drugs (droperidol 15 micrograms x kg-1 + dimenhydrinate 1 mg x kg-1) was administered after induction of anaesthesia and repeated 6 hours after the first administration. For general anaesthesia a standardised technique including benzodiazepine premedication, propofol, desflurane in N2O/O2, vecuronium, and a continuous infusion of remifentanil was used. Postoperative analgesia and antiemetic rescue medication were standardised. Episodes of vomiting, retching, nausea, and the need for additional antiemetics were recorded for 24 hours. The main goal of the study was to increase the number of patients who were completely free from PONV (chi 2-test with Fisher-Yates' correction). Furthermore, the severity of PONV was analysed using a standardised scoring algorithm.

RESULTS

Data of 227 patients could be analysed. The incidence of patients who suffered from PONV was 41.3% (95%-confidence interval: 29-55%) in the placebo-group. Dimenhydrinate alone reduced PONV to 34.5% (95%-CI: 22-48%). This marginal effect and the effect of droperidol (PONV: 26.4% (95%-CI: 15-40%)) could not be proven statistically, since the power of the study was too small. The combination of both drugs decreased PONV to 19.6% (95%-CI: 10-32%) and also reduced the severity of the symptoms to a clinically acceptable level.

CONCLUSION

Dimenhydrinate failed to reduce the incidence and severity of PONV. The efficiency of droperidol given alone was within the ranges previously known from metaanalytic data. The combination of both drugs showed a moderate synergistic effect.

Neuroleptic malignant syndrome induced by droperidol

A case of droperidol-induced neuroleptic malignant syndrome during anaesthesia is presented. An 86-year-old man underwent spinal anaesthesia for open reduction and internal fixation of a trochanteric hip fracture. He received droperidol 5 mg intravenously for sedation towards the end of surgery. He subsequently became very drowsy and experienced marked muscle rigidity and autonomic instability. He became febrile postoperatively. The clinical syndrome resolved after 12 hours. When using droperidol in anaesthesia or intensive care--especially when large doses are given--the development of neuroleptic malignant syndrome should be suspected if the patient becomes febrile and has muscle rigidity and autonomic instability.

Small-dose droperidol effectively reduces nausea in a general surgical adult patient population

In this prospective, randomized, placebo-controlled study, we (1) determined whether 0.625 mg of IV droperidol given 30 min before emergence from general anesthesia reduces the incidence of immediate and delayed postoperative nausea and vomiting (PONV) in a general surgical adult patient population, and (2) compared the efficacy of droperidol, ondansetron, and promethazine for the rescue treatment of PONV. One hundred fifty adult patients receiving general anesthesia for >2 h received either droperidol (0.625 mg IV) or a placebo before emergence. Patients requiring treatment for PONV in the postanesthesia care unit were randomized to receive either droperidol (0.625 mg IV), ondansetron (4 mg IV), or promethazine (12. 5 mg IV). Droperidol effectively prevented PONV (6.8% in droperidol-treated patients versus 40.8% in placebo-treated patients, P: < 0.001). Droperidol, ondansetron, and promethazine were equally effective in treating established PONV, without significant differences in side effects or time to postanesthesia care unit discharge.

IMPLICATIONS

Droperidol 0.625 mg IV before emergence from general anesthesia effectively reduces postoperative nausea and vomiting (PONV) in the general surgical population. Our randomized, double-blinded, placebo-controlled study demonstrated a reduction in PONV from 41% to 7%. Droperidol is a safe and inexpensive alternative to ondansetron. Droperidol, ondansetron, and promethazine are also equally effective in treating PONV in the postanesthesia care unit.

[Extrapyramidal reactions after epidural droperidol]

We report two patients who developed extrapyramidal reactions after epidural droperidol given to prevent postoperative nausea and vomiting. The reactions may have been related to interactions of drugs given perioperatively. One patient had been taking amlodipine and amitriptyline preoperatively, capable of causing extrapyramidal reactions, and developed akathisia after 2.5 mg of droperidol given epidurally. The other patient had received 1.5 mg of prophylactic epidural droperidol and 10 mg of metoclopramide for postoperative nausea and vomiting, and developed acute dystonia shortly after 0.5 mg of intravenous droperidol.

Efficacy, dose-response, and adverse effects of droperidol for prevention of postoperative nausea and vomiting

PURPOSE

To estimate the efficacy and harm produced by droperidol in the prevention of postoperative nausea and vomiting (PONV).

METHODS

Systematic search (MEDLINE, EMBASE, Cochrane library, hand-searching, bibliographies, all languages, up to May 1999) for randomised comparisons of droperidol with placebo in surgical patients. Relevant end points were prevention of early PONV (up to six hours postoperatively), and late PONV (24 hr), and adverse effects. Combined data were analysed using relative risk and NNT.

RESULTS

In 76 trials, 5,351 patients received 24 different regimens of droperidol. The average incidence of early and late PONV in controls was 34% and 51%, respectively. Droperidol was more efficacious than placebo in preventing PONV. In adults, the anti-nausea effect was short-lived, and there was no dose-responsiveness; with 0.25 to 0.30 mg the number-needed-to-treat (NNT) to prevent early nausea was 5. For both early and late anti-vomiting efficacy there was dose-responsiveness; best efficacy was with 1.5 mg to 2.5 mg (NNT, 7). In children, there was dose-responsiveness; best efficacy was with 75 microg x kg(-1) (NNT to prevent early and late vomiting, 4). Two children had extrapyramidal symptoms with droperidol (NNT in children, 91; in any patient, 408). There was dose-responsiveness for sedation and drowsiness (with 2.5 mg the NNT was 7.8). Droperidol prevented postoperative headache (NNT, -25).

CONCLUSIONS

Droperidol is anti-emetic in the surgical setting. The effect on nausea is short-lived but more pronounced than the effect on vomiting. Sedation and drowsiness are dose-dependent, extrapyramidal symptoms are rare, and there is a protective effect against headache.

Cost-effectiveness of prophylactic antiemetic therapy with ondansetron, droperidol, or placebo

BACKGROUND

In an era of growing economic constraints on healthcare delivery, anesthesiologists are increasingly expected to understand cost analysis and evaluate clinical practices. Postoperative nausea and vomiting (PONV) are distressing for patients and may increase costs in an ambulatory surgical unit. The authors compared the cost-effectiveness of four prophylactic intravenous regimens for PONV: 4 mg ondansetron, 0.625 mg droperidol, 1.25 mg droperidol, and placebo.

METHODS

Adult surgical outpatients at high risk for PONV were studied. Study drugs were administered intravenously within 20 min of induction of nitrous oxide-isoflurane or enflurane anesthesia. A decision-tree analysis was used to group patients into 12 mutually exclusive subgroups based on treatment and outcome. Costs were calculated for the prevention and treatment of PONV. Cost-effectiveness analysis was performed for each group.

RESULTS

Two thousand sixty-one patients were enrolled. Efficacy data for study drugs have been previously reported, and the database from that study was used for pharmacoeconomic analysis. The mean-median total cost per patient who received prophylactic treatment with 4 mg ondansetron, 0.625 mg droperidol, 1.25 mg droperidol, and placebo were $112 or $16.44, $109 or $0.63, $104 or $0.51, and $164 or $51.20, respectively (P = 0.001, active treatment groups vs. placebo). The use of a prophylactic antiemetic agent significantly increased patient satisfaction (P < 0.05). Personnel costs in managing PONV and unexpected hospital admission constitute major cost components in our analysis. Exclusion of nursing labor costs from the calculation did not alter the overall conclusions regarding the relative costs of antiemetic therapy.

CONCLUSION

The use of prophylactic antiemetic therapy in high-risk ambulatory surgical patients was more effective in preventing PONV and achieved greater patient satisfaction at a lower cost compared with placebo. The use of 1.25 mg droperidol intravenously was associated with greater effectiveness, lower costs, and similar patient satisfaction compared with 0.625 mg droperidol intravenously and 4 mg ondansetron intravenously.

Evaluating the usage of droperidol in acutely agitated persons with brain injury

The objective of this study was to compare the effectiveness and safety of intramuscular droperidol to other intramuscularly administered agents used in the management of acutely agitated patients. Twenty-seven inpatients with a history of brain injury were prospectively monitored over a period of 2 months. Data collected for each episode of agitation include: dose, number of doses, time to achieve an adequate response or calming effect, post-episodic functioning, treatment-emergent side effects, and other patient demographics. A retrospective medical records review was also performed on the same cohort, to compare clinical outcomes associated with other intramuscular agents previously used for acute agitation. Time to achieve calming was significantly shorter with intramuscular droperidol (mean = 27.0 minutes) compared to intramuscular haloperidol, lorazepam, or diphenhydramine (group mean = 36.2 minutes, p = 0.02). Of the three comparative agents, the time to achieve calming was the fastest with lorazepam (mean = 35.0 minutes), and slower with diphenhydramine (mean = 42.6 minutes) and haloperidol (mean = 43.0 minutes). Single doses of droperidol controlled agitation more frequently than did single doses of comparative agents, and there was less post-episodic sedation with droperidol following release from seclusion or restraints. Both groups were similar in regard to the incidence of treatment-emergent events. This data represents the first published experience supporting the effectiveness of droperidol in reducing acute agitation in persons with brain injury. Follow-up studies with prospective, double-blind, parallel treatment groups should be performed to validate these preliminary findings.

Additional droperidol, not butorphanol, augments epidural fentanyl analgesia following anorectal surgery

STUDY OBJECTIVE

To examine the effects of additional droperidol or butorphanol to epidural fentanyl infusion on postsurgical analgesia.

DESIGN

Prospective, randomized, single blinded clinical study.

SETTING

University-affiliated medical center.

PATIENTS

60 ASA physical status I and II patients undergoing anorectal surgery by one surgeon.

INTERVENTIONS

Patients were randomly allocated to the following groups according to the medication that was continuously administered into the epidural space: 1) Group C (n = 20) received 0.4 mg fentanyl in 40 ml of 0.125% bupivacaine; 2) Group D (n = 20) received 2.5 mg droperidol and 0.4 mg fentanyl in 40 ml of 0.125% bupivacaine; and 3) Group B (n = 20) received 2 mg butorphanol and 0.4 mg fentanyl in 40 ml of 0.125% bupivacaine over 24 hours postoperatively.

MEASUREMENTS AND MAIN RESULT

Postsurgical analgesia and the incidence of fentanyl-related complications, such as nausea/vomiting, somnolence, pruritus, and respiratory depression, were assessed for 24 hours postoperatively. At 16 and 24 hours after surgery, 75% of patients in Group D reported no pain versus 35% in Group C (p < 0.05). In addition, the overall visual analogue scale examined at 24 hours was significantly lower in Group D than that in Group C (22 +/- 17 mm vs. 44 +/- 22 mm, respectively; p < 0.05). Simultaneously, the incidence of postoperative nausea/vomiting was lower in Group D compared with Group C (20% vs. 60%; p < 0.05). On the other hand, butorphanol did not modify the analgesic effects or complications of epidural fentanyl infusion.

CONCLUSION

In this study population, additional droperidol, not butorphanol, improved postsurgical analgesia accompanied by less incidence of nausea/vomiting during epidural fentanyl administration.

Droperidol: efficacy and side effects in psychiatric emergencies

BACKGROUND

As admission criteria to inpatient units become more focused on patient safety and behavioral instability, primary treatment often requires use of medications that need to be quick, safe, and effective for control of agitation. This article reviews the evidence that droperidol may serve as the optimal medication for this task.

DATA SOURCES

A comprehensive MEDLINE search of English-language literature was conducted using the search term droperidol concerning the use of droperidol in psychiatric emergencies. Cross-referencing of those articles was conducted to include pertinent articles in the non-psychiatric and European literature regarding safety and early development of the drug.

STUDY FINDINGS

As evidenced in the animal and clinical literature, studies demonstrate the efficacy and rapidity of onset of droperidol and its relative safety compared with the most widely used antiagitation drug, haloperidol. Evidence for this use of droperidol is particularly compelling for situations in which intramuscular administration is necessary.

CONCLUSION

Droperidol, while not in widespread use, may prove to be the superior typical neuroleptic for psychiatric emergencies. Increased clinical utilization and study of droperidol for this use is warranted.

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.

Delayed akathisia and suicidal attempts following epidural droperidol infusion--a case report

Epidural administration of droperidol has been used to prevent postoperative nausea and vomiting (PONV) caused by opioids, but the adverse reactions were relatively neglected. We present a patient who received patient-controlled epidural analgesia (PCEA) with bupivacaine-morphine-droperidol mixture for one and half days following hemorrhoidectomy, developed paroxysmal adverse reactions of akathisia, dysphoria, and suicidal attempts 3 days after the initiation of the treatment. The use of droperidol in PCEA for prevention of nausea and vomiting therefore needs to be re-evaluated according to the serious side effects occurring in our case.

The antiemetic and dysphoric effects of droperidol in the day surgery patient

The incidence of side-effects of two doses of droperidol used as a prophylactic antiemetic were compared (10 vs 20 micrograms/kg). Two hundred and twenty-eight women for day case laparoscopy were recruited. Pain and nausea scores were collected in the recovery area and in the Day Surgery Unit prior to discharge. A telephone follow-up questionnaire was administered. Incidences of anxiety, restlessness and dysphoric reactions were similar in both groups (29.2% vs 29.0%). The incidence of postoperative vomiting varied from 4.4 to 7.7%. There were no significant differences between the two groups when nausea scores, incidences of vomiting and pain after discharge were compared. An unexpected finding was the significantly higher incidence of pain in the 10 micrograms/kg group. We conclude that there is no advantage in lowering the dose of droperidol below 20 micrograms/kg in this group of patients.

A randomized double-blind placebo-controlled trial evaluating the cost-effectiveness of droperidol as a sedative premedication for EUS

BACKGROUND

Droperidol is a neuroleptic agent with anti-emetic properties that produces mild sedation, reduced anxiety, and a state of mental detachment and indifference to one's surroundings. Routine premedication with droperidol has been shown to improve sedation during esophagogastroduodenoscopy and endoscopic retrograde cholangiopancreatography. The purpose of this randomized double-blind placebo-controlled study was to determine whether premedication with droperidol improves sedation during routine upper endoscopic ultrasound (EUS) in a cost-effective manner.

METHODS

One hundred consecutive patients referred for EUS were randomly assigned to receive either 2.5 mg or 5 mg of droperidol or placebo before the procedure. After EUS, the physician, nurse, and recovered patient scored various parameters of procedural sedation.

RESULTS

In the group receiving 5 mg of droperidol there was significantly less gagging at intubation, less retching during the procedure, better patient cooperation, less need for physical restraint, and improved nurses' and physician's impression of sedation. Significantly less meperidine and less midazolam were required for sedation, making medication costs significantly lower in the group receiving 5 mg droperidol.

CONCLUSIONS

A 5 mg dose of droperidol given as premedication for routine upper EUS improves sedation during the procedure while significantly decreasing the overall cost of sedation.

Extrapyramidal side-effects from droperidol mixed with morphine for patient-controlled analgesia in two children

We report two cases of extrapyramidal reactions occurring in children following the use of droperidol in combination with morphine for patient-controlled analgesia (PCA). Symptoms appeared 38 and 27 h, respectively, after commencement and after a total dose of 0.14 mg.kg-1 and 0.17 mg.kg-1, respectively. Although effective and safe in adult patients, we recommend caution with the use of droperidol-morphine mixtures for PCA in paediatric patients.

Droperidol for acute migraine headache

The use of intramuscular droperidol to treat acute migraine headache has not been previously reported in the emergency medicine literature. It is a promising therapy for migraine. The authors performed a pilot review of all patients receiving droperidol for migraine in our emergency department (ED) to evaluate its efficacy. We used a retrospective case series, in a suburban ED with an annual patient census of 48,000. All patients with a discharge diagnosis of migraine headache who were treated with i.m. droperidol during a consecutive 5-month period in our ED were identified. All patients received droperidol 2.5 mg intramuscular. As per ED protocol, their clinical progress was closely followed and documented at 30 minutes after drug administration (t30). Demographic and clinical variables were recorded on a standardized, closed-question, data collection instrument. The primary outcome measurement was relief of symptoms at t30 to the point that the patient felt well enough to go home without further ED intervention (symptomatic relief). Thirty-seven patients were treated (84% female), with an ED diagnosis of acute migraine with droperidol during the study period. The mean age was 36 +/- 12 years. Analgesics had been used within 24 hours before ED presentation by 62% of patients. At t30, 30 (81%) patients had symptomatic relief, 2 (5%) felt partial relief but required rescue medication, and 5 (14%) had no relief of symptoms. Drowsiness (14%) and mild akathisia (8%) were the only adverse reactions observed following drug administration. Droperidol 2.5 mg intramuscular may be a safe and effective therapy for the ED management of acute migraine headache. Randomized, controlled trials are warranted to further validate the findings of this preliminary study.

Cost-effectiveness of prophylactic dolasetron or droperidol vs rescue therapy in the prevention of PONV in ambulatory gynecologic surgery

PURPOSE

To assess the cost-effectiveness of prophylactic therapy (1.25 mg droperidol or 50 mg dolasetron i.v.) vs no prophylaxis (rescue therapy) for the prevention of post-operative nausea and vomiting (PONV) from a Canadian hospital perspective.

METHODS

DESIGN

A predictive decision analytic model using previously published clinical and economic evaluations, and costs of medical care in Canada.

SUBJECTS

Ambulatory gynecology surgery patients.

INTERVENTIONS

Three strategies administered prior to emergence from anesthesia were compared: 1.25 mg droperidol i.v., 50 mg dolasetron i.v.; and no prophylaxis (rescue therapy).

RESULTS

The base case mean cost per patient receiving dolasetron prophylaxis was $28.08 CAN compared with $26.88 CAN per patient receiving droperidol prophylaxis, resulting in a marginal cost of $1.20 CAN. This difference translated in an additional cost of $12.00 CAN for the dolasetron strategy per adverse event avoided over the droperidol strategy. The base case mean cost per patient not receiving prophylaxis was $26.92 resulting in marginal costs of $1.16 CAN and $0.04 CAN when compared to dolasetron and droperidol, respectively. Compared with the no prophylaxis strategy, dolasetron prophylaxis resulted in an incremental cost-effectiveness ratio of $5.82 CAN per additional PONV-free patient. The mean costs incurred per PONV-free patient were calculated to be $48.41 for the dolasetron strategy, $46.34 for the droperidol strategy and $70.83 for the no prophylaxis strategy.

CONCLUSIONS

Dolasetron and droperidol given intraoperatively were more cost-effective than no prophylaxis for PONV in patients undergoing ambulatory gynecologic surgery. The difference between the two agents was small and favoured droperidol. The model was robust to plausible changes through sensitivity analyses.

Comparative efficacy and safety of ondansetron, droperidol, and metoclopramide for preventing postoperative nausea and vomiting: a meta-analysis

Postoperative nausea and vomiting are important causes of morbidity after anesthesia and surgery. We performed a meta-analysis of published, randomized, controlled trials to determine the relative efficacy and safety of ondansetron, droperidol, and metoclopramide for the prevention of postoperative nausea and vomiting. We performed a literature search of English references using both the MEDLINE database and a manual search. Double-blinded, randomized, controlled trials comparing the efficiency of the prophylactic administration of ondansetron, droperidol, and/or metoclopramide therapy during general anesthesia were included. A total of 58 studies were identified, of which 4 were excluded for methodological concerns. For each comparison of drugs, a pooled odds ratio (OR) with a 95% CI was calculated using a random effects model. Ondansetron (pooled OR 0.43, 95% CI 0.31, 0.61; P < 0.001) and droperidol (pooled OR 0.68, 95% CI 0.54, 0.85; P < 0.001) were more effective than metoclopramide in preventing vomiting. Ondansetron was more effective than droperidol in preventing vomiting in children (pooled OR 0.49; P = 0.004), but they were equally effective in adults (pooled OR 0.87; P = 0.45). The overall risk of adverse effects was not different among drug combinations. We conclude that ondansetron and droperidol are more effective than metoclopramide in reducing postoperative vomiting.

IMPLICATIONS

We performed a systematic review of published, randomized, controlled trials to determine the relative efficacy and safety of ondansetron, droperidol, and metoclopramide for preventing postoperative nausea and vomiting. Ondansetron and droperidol were more effective than metoclopramide in reducing postoperative vomiting. The overall risk of adverse effects did not differ.

Efficacy and adverse effects of prophylactic antiemetics during patient-controlled analgesia therapy: a quantitative systematic review

Nausea and vomiting are frequent adverse effects of patient-controlled analgesia (PCA) with opioids. To identify the optimal prophylactic antiemetic intervention in this setting, we performed a systematic search for randomized trials (MEDLINE, EMBASE, Cochrane library, reference lists, hand-searching, no language restriction) published up to May 1998 that compared prophylactic antiemetic interventions with placebo or no treatment in the postoperative PCA-setting with opioids. Fourteen placebo-controlled trials (1117 patients) with different regimens of droperidol, ondansetron, hyoscine TTS, tropisetron, metoclopramide, propofol, and promethazine were analyzed. One PCA was with tramadol, all others were with morphine. At 24 h, the cumulative incidence of nausea and vomiting without antiemetics was approximately 50%. Droperidol 0.017-0.17 mg/mg of morphine (0.5-11 mg/d droperidol) was statistically significantly more effective than placebo without evidence of dose-responsiveness; the number needed to treat to prevent nausea compared with placebo was 2.7 (95% confidence interval 1.8-5.2), and that to prevent vomiting was 3.1 (2.3-4.8). Compared with placebo, the incidence of minor adverse effects with droperidol was increased with doses >4 mg/d.

IMPLICATIONS

Of 100 patients treated with droperidol added in a patient-controlled analgesia pump with morphine, 30 who would have vomited or been nauseated had they not received droperidol will not suffer these effects. There is no evidence of dose-responsiveness for efficacy with droperidol, but the risk of adverse effects is dose-dependent. There is a lack of evidence for other antiemetics.