Metabolism and elimination of quinine in healthy volunteers.

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Mirghani RA, Hellgren U, Bertilsson L, Gustafsson LL, Ericsson O

Metabolism and elimination of quinine in healthy volunteers.

Eur J Clin Pharmacol. 2003 Sep;59(5-6):423-7. doi: 10.1007/s00228-003-0637-8. Epub 2003 Aug 12.

PubMed ID

12920491 [ View in PubMed

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Abstract

OBJECTIVES: The aims were to investigate: (1) The renal elimination of quinine and its metabolites 3-hydoxyquinine, 2'-quininone, (10R) and (10S)-11-dihydroxydihydroquinine and (2) the relative importance of CYP3A4, CYP1A2 and CYP2C19 for the formation of 2'-quininone, (10R) and (10S)-11-dihydroxydihydroquinine in vivo. METHODS: In a randomised three-way crossover study, nine healthy Swedish subjects received a single oral dose of quinine hydrochloride (500 mg), on three different occasions: (A) alone, (B) concomitantly with ketoconazole (100 mg twice daily for 3 days) and (C) concomitantly with fluvoxamine (25 mg twice daily for 2 days). Blood and urine samples were collected before quinine intake and up to 96 h thereafter. All samples were analysed by means of high-performance liquid chromatography. RESULTS: Co-administration with ketoconazole significantly increased the area under the plasma concentration versus time curve (AUC) of 2'-quininone, (10S)-11-dihydroxydihydroquinine, and (10R)-11-dihydroxydihydroquinine, the geometric mean ratios (90% CI) of the AUC were 1.9 (1.8, 2.0), 1.3 (1.1, 1.7) and 1.6 (1.4, 1.8), respectively. Co-administration with fluvoxamine had no significant effect on the mean AUC of any of the metabolites. A mean of 56% of the administered oral quinine dose was recovered in urine after hydrolysis with beta-glucuronidase relative to the 40% recovered before hydrolysis. CONCLUSION: Quinine is eliminated in urine mainly as unchanged drug and as 3-hydroxyquinine. The major metabolite of quinine is 3-hydroxyquinine formed by CYP3A4. There is no evidence for the involvement of CYP3A4, 1A2 or 2C19 in the formation of 2'-quininone, (10S)-11-dihydroxydihydroquinine and (10R)-11-dihydroxydihydroquinine in vivo. Glucuronidation is an important pathway for the renal elimination of quinine, mainly as direct conjugation of the drug.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Quinine	Cytochrome P450 3A4	Protein	Humans	Unknown	Substrate Inhibitor Inducer	Details