Obstetrics & Gynecology · Medical Literature
Glycopyrronium Bromide versus Droperidol for Prophylaxis of Postoperative Nausea and Vomiting in Hysteroscopic Day Surgery: A Randomized, Double-Blind, Non-Inferiority Trial.
Abstract
To investigate the efficacy of glycopyrronium bromide in preventing postoperative nausea and vomiting (PONV) in patients undergoing gynecological hysteroscopic day surgery. This study is a prospective, randomized, double-blind, non-inferiority trial. The non-inferiority margin was set at 15%. Patients scheduled for elective gynecological hysteroscopic day surgery under general anesthesia from November 2025 to February 2026 were selected. A total of 260 eligible patients were randomly assigned to receive glycopyrronium bromide (Group G) or droperidol (Group F). Patients in Group G received intravenous glycopyrronium bromide 0.2 mg, while those in Group F received intravenous droperidol 1 mg. Surgery was performed under general anesthesia with remimazolam combined with alfentanil. The primary outcome observed was the incidence of PONV within 24 hours after surgery in both groups. Within 24 hours postoperatively, the incidence of nausea and vomiting in Group G was non-inferior to that in Group F (37.1% vs 34.1%, risk difference 3.0%; 95% confidence interval -9.0 to 14.7; upper limit < non-inferiority margin of 15%). In the PACU, the incidence of nausea and vomiting in Group G and Group F was 22.6% vs 17.9%, respectively (risk difference 4.7%; 95% confidence interval -5.4 to 14.6). Regarding perioperative adverse reactions, there was no statistically significant difference in the incidence of hypotension between the two groups(30.6% vs 39.8%, P=0.130). The incidence of bradycardia was higher in Group F than in Group G (7.3% vs 1.6%, P=0.030). Furthermore, the incidence of parched mouth was higher in Group G than in Group F (67.7% vs 15.4%, P=0.001). This study found that glycopyrronium bromide is non-inferior to droperidol in preventing PONV within 24 hours after gynecological hysteroscopic day surgery.
Clinical relevance
In adult women undergoing elective gynecological hysteroscopic day surgery under general anesthesia, is intravenous glycopyrronium bromide 0.2 mg non-inferior to intravenous droperidol 1 mg for prophylaxis of postoperative nausea and vomiting (PONV) within 24 hours postoperatively? __SNAPSHOT__ {"studyDesign":"Prospective, randomized, double-blind, two-arm, non-inferiority trial","setting":"Single center; Department of Anesthesiology, Weifang People's Hospital, Weifang, China. Enrollment: November 2025 – February 2026.","sampleSize":"n = 260 (Group G [glycopyrronium bromide]: 130; Group F [droperidol]: 130, per randomization allocation as reported)","population":"Adult women scheduled for elective gynecological hysteroscopic day surgery under general anesthesia. Predominantly young, non-smoking women — a population recognized as high-risk for PONV.","intervention":"Intravenous glycopyrronium bromide 0.2 mg (Group G), administered perioperatively. General anesthesia was conducted with remimazolam combined with alfentanil.","comparator":"Intravenous droperidol 1 mg (Group F), administered perioperatively under the same anesthetic regimen.","primaryOutcome":"Incidence of PONV (nausea and vomiting combined) within 24 hours postoperatively.","followUp":"24 hours postoperatively (including a PACU assessment phase).","fundingSource":"Not reported in the available abstract or full-text excerpt."}
Key findings
Primary outcome (24-hour PONV incidence): Group G (glycopyrronium bromide) 37.1% vs. Group F (droperidol) 34.1%; absolute risk difference +3.0% (95% CI: −9.0 to +14.7). The upper bound of the 95% CI (14.7%) fell below the pre-specified non-inferiority margin of 15%, meeting the non-inferiority criterion. A p-value for the primary non-inferiority test was not reported in the available abstract. NNH is not calculable from the reported data. In the PACU specifically, PONV incidence was 22.6% (Group G) vs. 17.9% (Group F); risk difference +4.7% (95% CI: −5.4 to +14.6), which did not cross the non-inferiority margin. Regarding adverse events: (1) Hypotension occurred in 30.6% (Group G) vs. 39.8% (Group F); difference not statistically significant (P = 0.130). (2) Bradycardia was significantly more frequent in Group F (droperidol) than Group G (7.3% vs. 1.6%; P = 0.030), representing a clinically meaningful safety advantage for glycopyrronium bromide. (3) Dry mouth (parched mouth) was markedly more common in Group G (67.7% vs. 15.4%; P = 0.001), a predictable anticholinergic adverse effect of glycopyrronium bromide and a relevant tolerability concern. No other adverse event data (e.g., QTc prolongation, sedation, extrapyramidal effects) were reported in the available excerpt.
Practice implications
This trial establishes that glycopyrronium bromide 0.2 mg IV is non-inferior to droperidol 1 mg IV for prevention of PONV within 24 hours in women undergoing hysteroscopic day surgery under remimazolam-alfentanil anesthesia, using a pre-specified 15% non-inferiority margin. Importantly, glycopyrronium bromide was associated with a statistically significant reduction in bradycardia compared to droperidol (1.6% vs. 7.3%), which may represent a meaningful safety advantage in this hemodynamically sensitive population. However, the high rate of dry mouth with glycopyrronium bromide (67.7%) is a substantial tolerability concern that must be weighed clinically, particularly in ambulatory day surgery patients. The absolute PONV rates in both groups were relatively high (>34%), suggesting that neither agent alone provides adequate prophylaxis in this high-risk population and that multimodal antiemetic strategies may still be warranted. Findings are limited in generalizability to: (1) the specific anesthetic regimen used (remimazolam + alfentanil); (2) a single Chinese tertiary center; (3) a female hysteroscopic surgery population; and (4) a short 3-month enrollment window. Whether results apply to other surgical populations, different anesthetic regimens, or male patients cannot be determined from this study. Practice change is not yet justified based on this single trial alone, but results are informative for centers already using or considering glycopyrronium bromide as an antiemetic, particularly where droperidol-related bradycardia or QTc concerns are relevant. Note: This summary is based on the published abstract and a limited full-text excerpt; full data tables, secondary outcomes, subgroup analyses, and complete adverse event profiles were not available for review. __LIMITATIONS__ Single-center trial at one Chinese institution, limiting generalizability to other healthcare settings, ethnicities, and surgical volumes.,The non-inferiority margin of 15% is relatively wide; the point estimate of the risk difference was +3.0%, meaning glycopyrronium bromide trended numerically higher in PONV rate, and the upper CI bound (14.7%) approached — though did not cross — the margin.,Both arms had high PONV incidence (>34%), raising questions about adequacy of baseline antiemetic prophylaxis and whether the comparator (droperidol 1 mg monotherapy) represents current best practice or guideline-recommended multimodal care.,General anesthesia with remimazolam-alfentanil is not universally used; results may not be applicable to propofol- or volatile anesthetic-based regimens.,Short enrollment window (3 months, November 2025–February 2026) may introduce seasonal or selection bias.,The extremely high rate of dry mouth in Group G (67.7%) is a major tolerability concern not fully contextualized in the available abstract; its impact on patient satisfaction, discharge readiness, or oral intake was not reported.,Blinding fidelity and allocation concealment methods are described as double-blind but details of the blinding procedure are not available in the excerpt.,Rescue antiemetic use, patient satisfaction scores, time to discharge, and quality of recovery were not reported in the available abstract.,Funding source is not reported, precluding assessment of potential conflict of interest.,Only an abstract and partial full-text excerpt were available for this summary; complete secondary outcomes, subgroup analyses, and per-protocol vs. intention-to-treat analyses could not be evaluated. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ In women undergoing hysteroscopic day surgery under remimazolam-alfentanil anesthesia, glycopyrronium bromide 0.2 mg IV met non-inferiority criteria versus droperidol 1 mg IV for 24-hour PONV prophylaxis and was associated with significantly less bradycardia, though it caused substantially more dry mouth (67.7%). These results are promising for settings where droperidol-related hemodynamic or cardiac adverse effects are a concern, but the high absolute PONV rates in both arms, single-center design, and specific anesthetic context limit immediate practice change pending confirmatory multicenter evidence.