Dextromethorphan and intrathecal morphine for analgesia after Caesarean section under spinal anaesthesia.

Abstract

BACKGROUND:

Dextromethorphan is an N-methyl-D-aspartic acid antagonist which can attenuate acute pain with few side-effects. In this prospective, randomized, double-blind study of dextromethorphan and intrathecal morphine, we investigated postoperative pain, pruritus, nausea and vomiting in women undergoing Caesarean section under spinal anaesthesia.

METHODS:

Women were allocated randomly to one of six groups, to receive intrathecal morphine 0.05, 0.1 or 0.2 mg plus oral dextromethorphan 60 mg or placebo.

RESULTS:

The addition of dextromethorphan did not reduce postoperative pain scores (P=0.83). Compared with women receiving intrathecal morphine 0.05 mg, women receiving higher doses had a significantly higher incidence of nausea and vomiting [odds ratio for intrathecal morphine 0.1 mg, 4.0 (95% confidence interval 1.2-14.1); for intrathecal morphine 0.2 mg, 7.9 (2.3-27.1)]. Compared with women receiving intrathecal morphine 0.05 mg, women receiving higher doses also had a significantly higher incidence of pruritus [odds ratio for intrathecal morphine 0.1 mg, 3.2 (95% confidence interval 1.3-8.2); for intrathecal morphine 0.2 mg, 3.7 (1.4-9.5)]. Women receiving dextromethorphan had a lower incidence of nausea and vomiting [odds ratio 2.6 (1.1-6.3)].

CONCLUSIONS:

Postoperative pain after Caesarean section under spinal anaesthesia was not reduced by the addition of oral dextromethorphan to a multimodal approach including intrathecal morphine.

• Authors: D M A Choi, A P Kliffer, M J Douglas
• Journal: British journal of anaesthesia (Br J Anaesth) Vol. 90 Issue 5 Pg. 653-8 (May 2003) ISSN: 0007-0912 [Print] England
• PMID: 12697594 (Publication Type: Clinical Trial, Journal Article, Randomized Controlled Trial)

Chemical References

• Analgesics, Opioid
• Excitatory Amino Acid Antagonists
• Receptors, N-Methyl-D-Aspartate
• Dextromethorphan
• Morphine

Topics

• Adult
• Analgesia, Obstetrical (methods)
• Analgesics, Opioid (administration & dosage, adverse effects)
• Anesthesia, Obstetrical (methods)
• Anesthesia, Spinal
• Cesarean Section
• Dextromethorphan (administration & dosage)
• Double-Blind Method
• Drug Administration Schedule
• Drug Therapy, Combination
• Excitatory Amino Acid Antagonists (therapeutic use)
• Female
• Humans
• Morphine (administration & dosage, adverse effects)
• Pain Measurement (methods)
• Pain, Postoperative (prevention & control)
• Postoperative Nausea and Vomiting (chemically induced, prevention & control)
• Pregnancy
• Prospective Studies
• Pruritus (chemically induced)
• Receptors, N-Methyl-D-Aspartate (antagonists & inhibitors)