Quantitative assessment of caffeine partial clearances in man

British Journal of Clinical Pharmacology
A LeloD J Birkett

Abstract

Five subjects who participated in an earlier study (Lelo et al., 1986b) of the comparative pharmacokinetics of caffeine (CA) and its primary monodemethylated metabolites paraxanthine (PX), theobromine (TB) and theophylline (TP) were administered CA to steady-state. Using areas under the plasma concentration-time curves for each of the dimethylxanthines derived from CA in the steady-state study and individual plasma clearances of PX, TB and TP determined in the previous study, the fractional conversion of CA to PX, TB and TP and the individual partial clearances of CA have been defined. The mean (+/- s.d.) fractional conversion of CA to PX, TB and TP was 79.6 +/- 21.0%, 10.8 +/- 2.4% and 3.7 +/- 1.3%, respectively. When only demethylation pathways are considered PX, TB and TP accounted for 83.9 +/- 5.4%, 12.1 +/- 4.1% and 4.0 +/- 1.4%, respectively of the CA demethylations. The mean partial clearance of CA to PX was approximately 8-fold and 23-fold greater than those to TB and TP respectively. These data confirm earlier reports that PX is the major metabolite of CA in humans but suggest that PX formation is quantitatively more important than previously believed.

References

Jul 1, 1978·Clinical Pharmacokinetics·R I Ogilvie
Apr 1, 1984·British Journal of Clinical Pharmacology·D M GrantW Kalow
Aug 1, 1982·Clinical Pharmacology and Therapeutics·A N KotakeH Josephs
Jan 1, 1983·European Journal of Clinical Pharmacology·J Blanchard, S J Sawers
Apr 1, 1983·Journal of Pharmacokinetics and Biopharmaceutics·J Blanchard, S J Sawers
Jan 1, 1981·Pharmacology & Therapeutics·J B Houston

❮ Previous
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Citations

Jan 1, 1989·Psychopharmacology·K N SternC E Johanson
Jan 1, 1988·European Journal of Clinical Pharmacology·S HarderP M Shah
Feb 1, 1988·Journal of Behavioral Medicine·J E JamesD J Birkett
Jan 4, 1989·Klinische Wochenschrift·A HolstegeW Gerok
Nov 18, 2008·Psychopharmacology·Merideth A AddicottPaul J Laurienti
Nov 2, 2005·European Journal of Clinical Pharmacology·Tashinga E BapiroCollen M Masimirembwa
Apr 25, 1990·European Journal of Pharmacology·S FerréM Casas
Mar 1, 1996·General Pharmacology·J O Miners, D J Birkett
Jun 9, 2001·Food and Chemical Toxicology : an International Journal Published for the British Industrial Biological Research Association·K WaltonA G Renwick
Nov 1, 1996·Comparative Biochemistry and Physiology. Part C, Pharmacology, Toxicology & Endocrinology·E TanakaS Kobayashi
Mar 10, 1998·Annals of Epidemiology·M A KlebanoffD G Wilkins
Sep 30, 2000·British Journal of Clinical Pharmacology·J T ForsythG T Tucker
Dec 1, 1998·Journal of Clinical Pharmacy and Therapeutics·E Tanaka
Oct 9, 2002·Clinical and Experimental Pharmacology & Physiology·John O Miners
Dec 24, 2005·Critical Reviews in Food Science and Nutrition·Faidon Magkos, Stavros A Kavouras
Jan 1, 1995·British Journal of Clinical Pharmacology·L J NotarianniB W Silverman
Dec 30, 1998·Pharmacology & Toxicology·B B RasmussenK Brøsen
May 1, 1995·Acta Physiologica Scandinavica·P SvenningssonB B Fredholm
Apr 1, 1989·Antimicrobial Agents and Chemotherapy·D P HealyM L Mooney
May 30, 2013·Applied Physiology, Nutrition, and Metabolism = Physiologie Appliquée, Nutrition Et Métabolisme·Juan Del CosoJesús Muñoz-Guerra
Jan 1, 1994·International Journal of Behavioral Medicine·J E James
Sep 9, 2010·Chemical & Pharmaceutical Bulletin·Toshinori SuzukiWolfgang Pfleiderer
Feb 22, 2012·PloS One·Juan Del CosoJesús Muñoz-Guerra
Sep 8, 2000·Clinical Pharmacokinetics·J A Carrillo, J Benitez
Jun 4, 2014·Pharmacology, Biochemistry, and Behavior·Jack E James
Apr 1, 1989·Xenobiotica; the Fate of Foreign Compounds in Biological Systems·F BerthouA Guillouzo
Dec 23, 2015·Microbial Cell Factories·Khalid H R AlgharrawiMani Subramanian
May 1, 2008·Environmental Toxicology and Pharmacology·Mihoko NumataRhonda J Rosengren
Nov 5, 2008·Human Psychopharmacology·Michael A Keane, Jack E James
Jan 1, 1993·Journal of Hepatology·A HolstegeW Gerok
May 18, 1994·Biochemical Pharmacology·W TassaneeyakulJ O Miners
Sep 30, 2005·Cytogenetic and Genome Research·W A RobbinsF Wei

❮ Previous
Next ❯

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