Prophylactic intravenous ondansetron reduces the incidence of intrathecal morphine-induced pruritus in patients undergoing cesarean delivery.
Pruritus is a common side effect of intrathecal morphine injection for postoperative pain control. Its incidence is especially high in patients undergoing cesarean delivery. We investigated the effectiveness of ondansetron in preventing intrathecal morphine-induced pruritus in such patients. We included 60 consecutive nonbreastfeeding women who were scheduled for elective cesarean delivery. After the administration of spinal anesthesia with bupivacaine and intrathecal morphine 0.15 mg injection, the patients were randomly divided into three groups. Group 1 received placebo (normal saline) IV injection, Group 2 diphenhydramine 30 mg IV injection, and Group 3 ondansetron 0.1 mg/kg IV injection. The incidence of pruritus was significantly lower in the ondansetron group (25%) when compared with that in the placebo group (85%) and in the diphenhydramine group (80%) (both P < 0.05). The postoperative pain score and time to flatus passage were not significantly different among the three groups. There were no headache or extrapyramidal signs associated with ondansetron use. In conclusion, ondansetron prophylaxis significantly reduced the incidence of intrathecal morphine-induced pruritus in patients undergoing cesarean delivery.


CONCLUSIONS
Ondansetron prophylaxis significantly decreases the incidence of pruritus, a common side effect of intrathecal morphine used to treat postcesarean delivery pain.
Yeh
H M
HM
Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan.
Chen
L K
LK
Lin
C J
CJ
Chan
W H
WH
Chen
Y P
YP
Lin
C S
CS
Sun
W Z
WZ
Wang
M J
MJ
Tsai
S K
SK
D000293:Adolescent; D000328:Adult; D016362:Analgesia, Obstetrical; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local; D000932:Antiemetics / Q000008:administration & dosage; D000982:Antipruritics / Q000008:administration & dosage; D002045:Bupivacaine; D002585:Cesarean Section; D004155:Diphenhydramine / Q000008:administration & dosage; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects*; D017294:Ondansetron / Q000008:administration & dosage*; D011247:Pregnancy; D011446:Prospective Studies; D011537:Pruritus / Q000139:chemically induced / Q000188:drug therapy / Q000517:prevention & control*; D012702:Serotonin Antagonists / Q000008:administration & dosage*
D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D000932:Antiemetics; D000982:Antipruritics; D012702:Serotonin Antagonists; D017294:Ondansetron; D009020:Morphine; D004155:Diphenhydramine; D002045:Bupivacaine