Time to First Rescue Antiemetic With Ondansetron Plus Metoclopramide Versus Dexamethasone Plus Metoclopramide for PONV Prophylaxis in Laparoscopic Cholecystectomy

The goal of this superiority randomized controlled trial (RCT) is to learn if one dual-drug arm increases patient comfort (time to needing rescue medication for nausea/vomiting) more effectively than the other in adults with Moderate-to-High PONV risk (Apfel score 2-4) undergoing elective laparoscopic cholecystectomy (gallbladder surgery). The main question this study aims to answer is: • Does Ondansetron plus Metoclopramide prolong time to first rescue antiemetic more than Dexamethasone plus Metoclopramide? Researchers will compare Group A (Ondansetron 4mg plus Metoclopramide 10mg IV) to Group B (Dexamethasone 8mg IV plus Metoclopramide 10mg IV) to see if Group A provides a longer time to first rescue medication. Participants will: * Receive their assigned, blinded drug group 5-10 minutes before general anesthesia induction. * Receive rescue Metoclopramide 10mg IV if they experience any vomiting or severe nausea * Be monitored for 24 hours post-surgery in the hospital * Report nausea severity at 2, 6, 12 and 24 hours post-surgery

Inclusion Criteria: * Age ≥ 18 years * American Society of Anesthesiologists (ASA) physical status I or II * Scheduled for elective laparoscopic cholecystectomy * Apfel score 2-4 (moderate to high risk for PONV) * Provides written informed consent prior to enrollment Exclusion Criteria: * Known allergy or hypersensitivity to ondansetron, dexamethasone, or metoclopramide * Emergency surgery (e.g., acute cholecystitis, perforation, or gangrene) * Pregnancy or breastfeeding * ASA physical status III or IV * Preexisting hepatic impairment * Baseline corrected QT (QTc) interval \> 420 ms on pre-operative ECG * History of dystonic reaction to metoclopramide or other dopamine antagonists * Preexisting renal impairment (e.g., serum creatinine \> 1.5 mg/dL or on dialysis) * Unable or unwilling to provide informed consent