Comparing the effect of Metoclopramide and ondansetron for preventing nausea and vomiting after cesarean section

Comparison of metoclopramide and ondansetron for preventing nausea and vomiting after cesarean section

Phase-III double-blind, randomized placebo-controlled trial with 3 parallel groups on 150 patients; randomization will be done with sealed envelopes

This study will be performed on 150 candidates of elective cesarean referred to the obstetric and gynecology wards fo Khalij Fars and Shariati Hospitals, Bandar Abbas. Patients will be randomized into 3 groups. Patients in the first intervention group will receive metoclopramide, the second intervention group ondansetron, and the control (placebo) group normal saline intravenously. Given that the drugs will be prepared in similar vials by an individual uninvolved in the study, the patients, nurses, investigator, and outcome assessor will be blinded to patient groupings (double-blind).

Inclusion criteria: age of 18-40 years old, ASA class I and II, candidate for elective cesarean section, singleton and term pregnancy. Non-inclusion criteria: contraindications of spinal anesthesia, history of postoperative nausea and vomiting, history of severe motion sickness, history of opioid abuse, gestational hypertension, preeclampsia, history of taking antiemetics one week before surgery

Intervention group 1: intravenous metoclopramide 10 mg/2 ml (DarouPakhsh Co., Iran) diluted with 8 ml normal saline Intervention group 2: intravenous ondansetron 4 mg/2 ml (Exir Co., Iran) diluted with 8 ml normal saline Control (placebo) group: 10 ml normal saline

Postoperative nausea and vomiting

Simple randomization with individuals as units of randomization along with allocation concealment: 150 opaque envelopes and 150 cards with the names of the groups (A, B, C) will be prepared (50 cards for each group). The cards will be put into the envelopes, and the envelopes will be sealed and provided to the investigator. Upon entrance of each patient to the study, the envelopes will be shuffled, and one will randomly be selected. The patient will be allocated to groups A, B, or C based on the card inside the selected envelope.

Metoclopramide, ondansetron, and normal saline have the same color, and an identical volume of these drugs (10 ml) will be administered. These drugs will be prepared in similar vials by an individual uninvolved in the study. Therefore, the patients, the caregivers, the investigator, and the outcome assessor will be unaware of the injected drug for each patient.