Addition of intramuscular promethazine to ondansetron does not reduce intrathecal morphine related side effects after cesarean

This was a prospective double blind placebo controlled trial adding prophylactic intramuscular promethazine to intravenous ondansetron with the aim to reduce nausea, vomiting and itching after spinal anesthesia with intrathecal morphine for cesarean delivery. Participants were undergoing scheduled cesarean delivery under standard spinal anesthesia with intrathecal morphine 100 mcg. All patients received intravenous ondansetron 4 mg prior to surgery. Then, all patients had an intramuscular injection of 1 mL containing either normal saline placebo or promethazine 25 mg. Patients were then asked to rate their pruritus (ItchyQuant scale), nausea/vomiting (yes/no), sedation (RASS scale) and pain (DVPRS scale) at 1 hour, 4 hours and 24 hours after study drug administration. The data set also contains basic demographic information and obstetric history.