Comparison of Palonosetron, Dexamethasone, and Palonosetron Plus Dexamethasone as Prophylactic Antiemetic and Antipruritic Drug in Patients Receiving Intrathecal Morphine for Lower Segment Cesarean Section

BACKGROUND: Intrathecal morphine is commonly used for postcesarean analgesia. Its use is frequently associated with opioid-induced nausea, vomiting, and pruritus. Palonosetron (0.075 mg) combined with dexamethasone (8 mg) is postulated to have an additive effect over each drug alone. The study, therefore, compared the effect of intravenous (i.v.) palonosetron, dexamethasone, and palonosetron with dexamethasone combination in preventing intrathecal morphine-induced postoperative vomiting and pruritus in lower segment cesarean section (LSCS) patients. SETTINGS AND DESIGN: Randomized, prospective, double-blinded, observational clinical study. METHODS: Ninety pregnant women, American Society of Anesthesiologists physical status class I undergoing LSCS were included in the study. They were randomly assigned to three groups – Group P received 0.075 mg palonosetron i.v., Group D received dexamethasone 8 mg i.v., and Group PD received palonosetron 0.075 mg along with dexamethasone 4 mg i.v., just after spinal anesthesia with bupivacaine 2.2 ml (12 mg) and 150 μg morphine. The incidence of pruritus, nausea, vomiting, and need for rescue drug were recorded for 24 h. STATISTICAL ANALYSIS: Statistical analysis was performed using Student's t-test for categorical variables and Chi-square test for noncategorical variables. RESULTS: The incidence of nausea, vomiting was significantly more in Group D (40%) than Group P (27%) and Group PD (20%) in 24 h. The incidence of pruritus was significantly more in Group D (6%) than Group P and PD (3%). The need of rescue antiemetic was more in Group D (30%) than Group P (6%) and Group PD (3%). No difference in three groups requiring rescue antipruritic drug. CONCLUSION: Prevention of intrathecal morphine-induced vomiting and pruritus was more effective with palonosetron alone or with dexamethasone combination than dexamethasone alone. Combination of palonosetron and dexamethasone proved no better than palonosetron alone.