title: Analgesic responses to intrathecal morphine in relation to CSF concentrations of morphine-3,beta-glucuronide and morphine-6,beta-glucuronide.
abstract: This study was performed to determine whether variations in analgesic responses to intrathecal morphine could be explained by cerebrospinal fluid (CSF) concentrations of morphine metabolites. Twenty-four CSF samples were collected at the beginning, middle and end of treatment periods in seven cancer patients with pain of malignant origin. CSF concentrations of morphine-3,beta-glucuronide (M3G) and morphine-6,beta-glucuronide (M6G) metabolites were measured by gas chromatography/mass spectrometry. Analgesic responses to morphine were estimated concurrent with CSF collection using a visual analog scale representing percentages of pain relief. Effective analgesia was defined as > or = 75% pain relief. CSF concentration of M3G and M6G in the 24 samples were 722 +/- 116 ng/ml and 699 +/- 158 ng/ml, respectively. CSF samples were categorized into two groups: (1) those collected during effective analgesia (N=14), and (2) those collected during ineffective analgesia (N=10). M6G levels detected in group 1 samples (effective analgesia) were significantly greater than those found in group 2 samples (ineffective analgesia) (978 +/- 243 ng/ml vs 309 +/- 68 ng/ml, P<0.05). Intergroup differences in CSF M3G concentrations and M3G/M6G ratios were not significant. It is concluded that CSF M6G may be indicative of effectiveness of analgesia in cancer patients subjected to intrathecal morphine.
authors.affiliation: Department of Surgery, Howard University Hospital, Washington, DC 20060, USA.
authors.forename: G C
authors.initials: GC
authors.lastname: Dennis
authors.forename: D
authors.initials: D
authors.lastname: Soni
authors.forename: O
authors.initials: O
authors.lastname: Dehkordi
authors.forename: R M
authors.initials: RM
authors.lastname: Millis
authors.forename: H
authors.initials: H
authors.lastname: James
authors.forename: W L
authors.initials: WL
authors.lastname: West
authors.forename: R E
authors.initials: RE
authors.lastname: Taylor
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009022:Morphine Derivatives / Q000134:cerebrospinal fluid*
chemical_list: D000701:Analgesics, Opioid; D009022:Morphine Derivatives; C035349:morphine-6-glucuronide; D009020:Morphine; C018108:morphine-3-glucuronide