Peixoto 2006.

Study characteristics
Methods	RCT
Participants	120 women undergoing elective CS under spinal anaesthesia, ASA 1‐2, no pre‐op emesis or antiemetic medications within 24 hours.
Interventions	Intervention 1: 5‐HT3antagonist (Comparison 1) Ondansetron 4 mg. N = 40. Intervention 2: dopamine antagonist (Comparson 2) Droperidol 1.25 mg. N = 40. Comparison: placebo Normal saline. N = 40.
Outcomes	Nausea and vomiting up to 24 hours postoperative, adverse events.
Notes	Setting: Erechim, Brazil and Yale, Conneticut, USA. Dates: April 2001 to August 2003 Funding source: not reported. Declaration of interest: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation code.
Allocation concealment (selection bias)	Unclear risk	Sealed envelopes, syringes prepared by member of research team not involved in care.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	All personnel unaware of allocation.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	All personnel unaware of allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Nil.
Selective reporting (reporting bias)	Unclear risk	We did not assess the trial protocol.
Other bias	Low risk	No significant differences reported on.