BACKGROUND AND AIMS:Spinalanaesthesia is considered as gold standard technique for cesareansections but the side effects of spinal anesthesia are hypotension, bradycardia and shivering.Serotonin released during the low volume states has been suggested as a possible trigger for the Bezold–Jarischreflex(BJR) that may lead to the bradycardia and hypotension.

OBJECTIVE:To comparebetween two serotonin receptor antagonistsondensetronandgranisetron and traditionally used vasopressor ‘ephedrine’ on hemodynamics, sensory and motor blockade during spinal anesthesia in cesarean delivery.

SETTINGS  AND DESIGN:This settingwas designed as a double–blind,prospective,randomized controlled study.

MATERIALS  AND METHODS:A total number of 90 patients of ASA grade 1 &2 of age between 20–30 years undergoing lowersegment cesarean section were randomly allocated into 3 equal groups .Group A received 1mggranisetron, Group B received 4mgondensetron, Group C received 10mg ephedrine. All of these studied groups were diluted in 10 ml normal saline and administered over a period of 1–5 min before induction of spinal anesthesia. Mean arterial blood pressure, heart rate, rescue of vasopressor, sensory and motor blockade were assessed.

RESULTS:The incidence of hypotension and need of rescue vasopressor  is significantly lower(p<0.05) in Group B than in group A & C.There is significant faster sensory and motor recovery in Group A than in group B& C.

CONCLUSION:In parturients undergoing cesarean section I.V 4mgondensetron before giving spinal anesthesia decreased both the hypotension and the doses of vasopressorrecquired.