Lack of effect of ondansetron on the pharmacokinetics and analgesic effects of morphine and metabolites after single-dose morphine administration in healthy volunteers.

Journal Article

The purpose of this investigation was to study the influence of ondansetron on the single-dose pharmacokinetics and the analgesic effects elicited by morphine and the 3- and 6-glucuronide metabolites of morphine in healthy volunteers.This was a randomized, double-blind, placebo-controlled, two-way crossover study in which six male and six female subjects were administered a single 10 mg intravenous dose of morphine sulphate, followed 30 min later by a single 16 mg intravenous dose of ondansetron hydrochloride or placebo. Serum and urine concentrations of morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) samples were quantified over 48 h using high performance liquid chromatography with detection by mass spectrometry. Analgesia was assessed in the volunteers with a contact thermode device to provide a thermal pain stimulus. Four analgesic response variables were measured including thermal pain threshold, thermal pain tolerance, temporal summation of pain and mood state.The two treatments appeared to be equivalent based on the 90% confidence intervals (0.6, 1.67) of the least squares means ratio. All least squares means ratio confidence intervals for each parameter, for each analyte fell within the specified range, demonstrating a lack of an interaction.The results of this study suggest that administration of ondansetron (16 mg i.v.) does not alter the pharmacokinetics of morphine and its 3- or 6-glucuronide metabolites to a clinically significant extent, nor does it affect the overall analgesic response to morphine as measured by the contact thermode system.

Full Text

Duke Authors

Cited Authors

  • Crews, KR; Murthy, BP; Hussey, EK; Passannante, AN; Palmer, JL; Maixner, W; Brouwer, KL

Published Date

  • April 2001

Published In

Volume / Issue

  • 51 / 4

Start / End Page

  • 309 - 316

PubMed ID

  • 11318765

Electronic International Standard Serial Number (EISSN)

  • 1365-2125

International Standard Serial Number (ISSN)

  • 0306-5251

Digital Object Identifier (DOI)

  • 10.1046/j.1365-2125.2001.01369.x


  • eng