Skip to main content
Advertisement

Main menu

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET

User menu

  • My alerts
  • Log in
  • Log out
  • My Cart

Search

  • Advanced search
Journal of Pharmacology and Experimental Therapeutics
  • Other Publications
    • Drug Metabolism and Disposition
    • Journal of Pharmacology and Experimental Therapeutics
    • Molecular Pharmacology
    • Pharmacological Reviews
    • Pharmacology Research & Perspectives
    • ASPET
  • My alerts
  • Log in
  • Log out
  • My Cart
Journal of Pharmacology and Experimental Therapeutics

Advanced Search

  • Home
  • Articles
    • Current Issue
    • Fast Forward
    • Latest Articles
    • Archive
  • Information
    • Instructions to Authors
    • Submit a Manuscript
    • FAQs
    • For Subscribers
    • Terms & Conditions of Use
    • Permissions
  • Editorial Board
  • Alerts
    • Alerts
    • RSS Feeds
  • Virtual Issues
  • Feedback
  • Visit jpet on Facebook
  • Follow jpet on Twitter
  • Follow jpet on LinkedIn
Research ArticleABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION

Extrapolation of Diclofenac Clearance from in Vitro Microsomal Metabolism Data: Role of Acyl Glucuronidation and Sequential Oxidative Metabolism of the Acyl Glucuronide

Sanjeev Kumar, Koppara Samuel, Ramaswamy Subramanian, Matthew P. Braun, Ralph A. Stearns, Shuet-Hing Lee Chiu, David C. Evans and Thomas A. Baillie
Journal of Pharmacology and Experimental Therapeutics December 2002, 303 (3) 969-978; DOI: https://doi.org/10.1124/jpet.102.038992
Sanjeev Kumar
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Koppara Samuel
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Ramaswamy Subramanian
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Matthew P. Braun
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Ralph A. Stearns
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Shuet-Hing Lee Chiu
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
David C. Evans
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Thomas A. Baillie
Department of Drug Metabolism, Merck Research Laboratories, Rahway, New Jersey
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Figures & Data
  • Info & Metrics
  • eLetters
  • PDF
Loading

Abstract

Diclofenac is eliminated predominantly (∼50%) as its 4′-hydroxylated metabolite in humans, whereas the acyl glucuronide (AG) pathway appears more important in rats (∼50%) and dogs (>80–90%). However, previous studies of diclofenac oxidative metabolism in human liver microsomes (HLMs) have yielded pronounced underprediction of human in vivo clearance. We determined the relative quantitative importance of 4′-hydroxy and AG pathways of diclofenac metabolism in rat, dog, and human liver microsomes. Microsomal intrinsic clearance values (CLint =V max/K m) were determined and used to extrapolate the in vivo blood clearance of diclofenac in these species. Clearance of diclofenac was accurately predicted from microsomal data only when both the AG and the 4′-hydroxy pathways were considered. However, the fact that the AG pathway in HLMs accounted for ∼75% of the estimated hepatic CLint of diclofenac is apparently inconsistent with the 4′-hydroxy diclofenac excretion data in humans. Interestingly, upon incubation with HLMs, significant oxidative metabolism of diclofenac AG, directly to 4′-hydroxy diclofenac AG, was observed. The estimated hepatic CLint of this pathway suggested that a significant fraction of the intrahepatically formed diclofenac AG may be converted to its 4′-hydroxy derivative in vivo. Further experiments indicated that this novel oxidative reaction was catalyzed by CYP2C8, as opposed to CYP2C9-catalyzed 4′-hydroxylation of diclofenac. These findings may have general implications in the use of total (free + conjugated) oxidative metabolite excretion for determining primary routes of drug clearance and may question the utility of diclofenac as a probe for phenotyping human CYP2C9 activity in vivo via measurement of its pharmacokinetics and total 4′-hydroxy diclofenac urinary excretion.

  • The American Society for Pharmacology and Experimental Therapeutics
View Full Text

JPET articles become freely available 12 months after publication, and remain freely available for 5 years. 

Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page. 

 

  • Click here for information on institutional subscriptions.
  • Click here for information on individual ASPET membership.

 

Log in using your username and password

Forgot your user name or password?

Purchase access

You may purchase access to this article. This will require you to create an account if you don't already have one.
PreviousNext
Back to top

In this issue

Journal of Pharmacology and Experimental Therapeutics: 303 (3)
Journal of Pharmacology and Experimental Therapeutics
Vol. 303, Issue 3
1 Dec 2002
  • Table of Contents
  • Index by author
Download PDF
Article Alerts
Sign In to Email Alerts with your Email Address
Email Article

Thank you for sharing this Journal of Pharmacology and Experimental Therapeutics article.

NOTE: We request your email address only to inform the recipient that it was you who recommended this article, and that it is not junk mail. We do not retain these email addresses.

Enter multiple addresses on separate lines or separate them with commas.
Extrapolation of Diclofenac Clearance from in Vitro Microsomal Metabolism Data: Role of Acyl Glucuronidation and Sequential Oxidative Metabolism of the Acyl Glucuronide
(Your Name) has forwarded a page to you from Journal of Pharmacology and Experimental Therapeutics
(Your Name) thought you would be interested in this article in Journal of Pharmacology and Experimental Therapeutics.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Research ArticleABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION

Extrapolation of Diclofenac Clearance from in Vitro Microsomal Metabolism Data: Role of Acyl Glucuronidation and Sequential Oxidative Metabolism of the Acyl Glucuronide

Sanjeev Kumar, Koppara Samuel, Ramaswamy Subramanian, Matthew P. Braun, Ralph A. Stearns, Shuet-Hing Lee Chiu, David C. Evans and Thomas A. Baillie
Journal of Pharmacology and Experimental Therapeutics December 1, 2002, 303 (3) 969-978; DOI: https://doi.org/10.1124/jpet.102.038992

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Share
Research ArticleABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION

Extrapolation of Diclofenac Clearance from in Vitro Microsomal Metabolism Data: Role of Acyl Glucuronidation and Sequential Oxidative Metabolism of the Acyl Glucuronide

Sanjeev Kumar, Koppara Samuel, Ramaswamy Subramanian, Matthew P. Braun, Ralph A. Stearns, Shuet-Hing Lee Chiu, David C. Evans and Thomas A. Baillie
Journal of Pharmacology and Experimental Therapeutics December 1, 2002, 303 (3) 969-978; DOI: https://doi.org/10.1124/jpet.102.038992
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Jump to section

  • Article
    • Abstract
    • Materials and Methods
    • Results
    • Discussion
    • Acknowledgments
    • Footnotes
    • Abbreviations
    • References
  • Figures & Data
  • Info & Metrics
  • eLetters
  • PDF

Related Articles

Cited By...

More in this TOC Section

  • Transport Is Not Rate-Limiting in Morphine Glucuronidation in the Single-Pass Perfused Rat Liver Preparation
  • Enhanced Hepatic Uptake and Bioactivity of Type α1(I) Collagen Gene Promoter-Specific Triplex-Forming Oligonucleotides after Conjugation with Cholesterol
  • Characterization of P-glycoprotein Inhibition by Major Cannabinoids from Marijuana
Show more ABSORPTION, DISTRIBUTION, METABOLISM, AND EXCRETION

Similar Articles

  • Home
  • Alerts
Facebook   Twitter   LinkedIn   RSS

Navigate

  • Current Issue
  • Fast Forward by date
  • Fast Forward by section
  • Latest Articles
  • Archive
  • Search for Articles
  • Feedback
  • ASPET

More Information

  • About JPET
  • Editorial Board
  • Instructions to Authors
  • Submit a Manuscript
  • Customized Alerts
  • RSS Feeds
  • Subscriptions
  • Permissions
  • Terms & Conditions of Use

ASPET's Other Journals

  • Drug Metabolism and Disposition
  • Molecular Pharmacology
  • Pharmacological Reviews
  • Pharmacology Research & Perspectives
ISSN 1521-0103 (Online)

Copyright © 2021 by the American Society for Pharmacology and Experimental Therapeutics