Ondansetron given intravenously attenuates arterial blood pressure drop due to spinal anesthesia: a double-blind, placebo-controlled study.

Background And Objectives: Side effects of spinal anesthesia include arterial hypotension and bradycardia. Both of them may be induced by sympathetic nerve blockade as well as by the Bezold-Jarisch reflex, which may be mediated by peripheral serotonin receptors (5-HT(3) type). The aim of this study was to verify the hypothesis that blockade of type 3 serotonin receptors by intravenous ondansetron administration might reduce hypotension and bradycardia induced by spinal anesthesia.