Factors impacting variability of the urinary normeperidine-to-meperidine metabolic ratio in patients with chronic pain.

Abstract

Meperidine (Demerol(®)) is a mu- and kappa-opiate receptor agonist used for moderate to severe pain. Overdose can result in respiratory depression, hypotension and coma, while accumulation of its toxic metabolite, normeperidine, can cause delirium and seizures. Little data exist examining the inter- and intrasubject variability of the normeperidine-to-meperidine metabolic ratio (MR) in urine. This retrospective data analysis examined meperidine and normeperidine urine concentrations collected from chronic pain patients. In 98 subjects with multiple visits, the geometric mean urinary MR = 6.1 (coefficient of variation, %CV = 68%). From single specimens obtained from 799 subjects, the geometric mean urinary MR = 6.2 (%CV = 212%). The urinary MR increased in young subjects compared with elderly (P = 0.004) and middle-aged subjects (P = 0.01). A 27% difference was found between the male and female urinary MR (male geometric mean MR = 5.1, female geometric mean MR = 7.0, P = 0.02). Intersubject variability in meperidine metabolism was 3-fold greater than intrasubject variability. A significant difference in the urinary MR was found between males and females. The substantial variability in meperidine metabolism and the serious side effects of its metabolite normeperidine require greater vigilance in patient medication monitoring.

• Authors: Katie V Moy, Joseph D Ma, Brookie M Best, Rabia S Atayee
• Journal: Journal of analytical toxicology (J Anal Toxicol) 2014 Jan-Feb Vol. 38 Issue 1 Pg. 1-7 ISSN: 1945-2403 [Electronic] England
• PMID: 24133175 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cholinesterase Inhibitors
• Receptors, Opioid
• Meperidine
• normeperidine

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Cholinesterase Inhibitors (administration & dosage, urine)
• Chromatography, Liquid
• Chronic Pain (drug therapy, urine)
• Female
• Humans
• Hydrogen-Ion Concentration
• Linear Models
• Male
• Meperidine (administration & dosage, analogs & derivatives, urine)
• Middle Aged
• Receptors, Opioid (agonists, metabolism)
• Retrospective Studies
• Tandem Mass Spectrometry
• Young Adult