A high-performance liquid chromatographic method has been developed for the detection, separation and measurement of codeine and its metabolites norcodeine, morphine and normorphine, with their glucuronide conjugates. The glucuronidase Escherichia coli type VIIA hydrolyses codeine-6-glucuronide completely and is used for the construction of the calibration curves of codeine-6-glucuronide. Enzymic hydrolysis of codeine-6-glucuronide depends on the specific activity of the glucuronidase applied. Examples are shown of a volunteer who is able to form morphine from codeine and one who is unable to do so.
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http://dx.doi.org/10.1016/0378-4347(91)80534-j | DOI Listing |
BMC Vet Res
May 2022
K.L. Maddy Equine Analytical Pharmacology Laboratory, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
Background: In humans, codeine is a commonly prescribed analgesic that produces its therapeutic effect largely through metabolism to morphine. In some species, analgesic effects of morphine have also been attributed to the morphine-6-glucuronide (M6G) metabolite. Although an effective analgesic, administration of morphine to horses produces dose-dependent neuroexcitation at therapeutic doses.
View Article and Find Full Text PDFJ Anal Toxicol
March 2021
Division of Drug Research, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, 581 83, Linköping, Sweden.
Analysis of postmortem samples with the presence of morphine can sometimes be challenging to interpret. Tolerance complicates interpretation of intoxications and causes of death due to overlap in therapeutic and fatal concentrations. Determination of metabolites and metabolic ratios can potentially differentiate between abstinence, continuous administration, and perhaps time of administration.
View Article and Find Full Text PDFVet Anaesth Analg
September 2020
K.L. Maddy Equine Analytical Pharmacology Laboratory, University of California-Davis, School of Veterinary Medicine, Davis, CA, USA; Department of Veterinary Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, CA, USA. Electronic address:
Objective: To describe the pharmacokinetics and selected pharmacodynamic variables of codeine and its metabolites in Thoroughbred horses following a single oral administration.
Study Design: Prospective experimental study.
Animals: A total of 12 Thoroughbred horses, nine geldings and three mares, aged 4-8 years.
J Chromatogr B Analyt Technol Biomed Life Sci
September 2020
Department of Pharmacology, E.A.3801, SFR CAP-santé, Reims University Hospital, 51, rue Cognacq-Jay, 51095 Reims Cedex, France. Electronic address:
Opioids represent a broad family of compounds that can be used in several indications: analgesics, antitussives, opioid substitution therapy (e.g. methadone, buprenorphine…).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!