Effect of Intravenous Ondansetron on Sensory and Motor Block after Spinal Anaesthesia with Hyperbaric Bupivacaine

Abstract

Ondansetron is a potent antiemetic and a competitive antagonist at serotonin receptors, which are also involved in modulation of pain. This study was designed to assess the effect of systemic ondansetron on sensory and motor block after subarachnoid anaesthesia with hyperbaric bupivacaine. Sixty patients undergoing transurethral resection of bladder tumours were randomly assigned to one of two groups. Group 1 received 2 ml (4 mg) of ondansetron whereas patients in group 2 received 2 ml of normal saline 15 minutes prior to administration of subarachnoid block with 2.5 ml of hyperbaric bupivacaine 0.5%. Time to attain peak sensory block (P=0.27), time to two segment regression (P=0.19) and time to regression to the S 2 dermatome (P=0.84) did not significantly differ between the two groups. No differences in regression of sensory block were noted at any time. The mean duration of motor block also did not differ (P=0.44), with similar regression of block at all time intervals except at 90 minutes. We concluded that intravenous ondansetron does not affect the intensity or duration of sensory and motor block after spinal anaesthesia with hyperbaric bupivacaine.

Ondansetron Does Not Attenuate Hemodynamic Changes in Patients Undergoing Elective Cesarean Delivery Using Subarachnoid Anesthesia

“…Our study also confirms the finding that ondansetron does not affect the density of both sensory and motor blocks after subarachnoid anesthesia. 23 Our results suggest that ondansetron 8 mg is not effective in attenuating hypotension after subarachnoid anesthesia. However, there are limitations to our study.…”

Comparison of IV granisetron and IV palonosetron on hemodynamics and sensory and motor block after spinal anesthesia with hyperbaric bupivacaine in patients undergoing abdominal hysterectomy

“…Similar results have also been seen with ondansetron administered to patient prior to spinal anesthesia. [81516]…”

“…Similar lack of effects on motor blockade has also been seen in other studies using other 5-HT3 receptors antagonists. [789151619]…”

The intravenously administered palonosetron does not affect the spinal anesthesia

“…In one study, ondansetron administered to prevent nausea and vomiting interrupted sensory deprivation in spinal anesthesia performed with lidocain [2]. Another study showed that other 5-HT3 antagonists such as granisetron enhanced recovery of the sensory nerves during spinal anesthesia [3]. Palonosetron, a second-generation 5-HT3 receptor antagonist approved in 2003, is known to have the strongest affinity to the 5-HT3 receptor, with a receptor binding affinity about 30 times stronger than that of ondansetron and granisetron.…”