In Vivo Investigation in Pigs of Intestinal Absorption, Hepatobiliary Disposition, and Metabolism of the 5α-Reductase Inhibitor Finasteride and the Effects of Coadministered Ketoconazole

February 2011 in “ Drug Metabolism and Disposition ”

Anna Lundahl, Mikael Hedeland, Ulf Bondesson, Hans Lennernäs

finasteride 5α-reductase inhibitor ketoconazole male pattern baldness Propecia

From the encyclopedia

Finasteride →

Frontline, gold standard treatment for combatting androgenic alopecia

Ketoconazole →

antifungal with some anti-androgenic benefits, often used as a shampoo

Studysummary This study examined the pharmacokinetics of finasteride in pigs and found that ketoconazole coadministration affected its distribution across various plasma compartments, bile, and urine. Our plain-language summary of this paper — not a Tressless recommendation.

This study investigated the pharmacokinetics and metabolism of finasteride, a 5α-reductase inhibitor used to treat benign prostatic hyperplasia and male pattern baldness, in pigs. The study found that ketoconazole increased the bioavailability of finasteride and the terminal half-life. The liver extraction ratio was time-dependent and varied with the two routes of administration. After intrajejunal administration, the liver extraction ratio was significantly reduced by ketoconazole treatment. The study provides valuable insights into the pharmacokinetics of finasteride and its interactions with other drugs.

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Research cited in this study

6 / 6 results

research Saturable Binding of Finasteride to Steroid 5α-Reductase as Determinant of Nonlinear Pharmacokinetics

16 citations , January 2010 in “Drug Metabolism and Pharmacokinetics”

This study developed a pharmacokinetic/pharmacodynamic model for finasteride, concluding that finasteride's nonlinear pharmacokinetics are likely due to its saturable binding to 5alphaR2.

Identification of Finasteride Metabolites in Human Bile and Urine by High-Performance Liquid Chromatography/Tandem Mass Spectrometry

research Identification of Finasteride Metabolites in Human Bile and Urine by High-Performance Liquid Chromatography/Tandem Mass Spectrometry

18 citations , July 2009 in “Drug Metabolism and Disposition”

This study identified previously unknown phase I and phase II metabolites of finasteride in human bile and urine using a specialized bile collection technique and advanced mass spectrometry analysis.

The Effect of St. John's Wort on the Pharmacokinetics, Metabolism, and Biliary Excretion of Finasteride and Its Metabolites in Healthy Men

research The Effect of St. John's Wort on the Pharmacokinetics, Metabolism, and Biliary Excretion of Finasteride and Its Metabolites in Healthy Men

33 citations , November 2008 in “European Journal of Pharmaceutical Sciences”

This study found that St. John's wort treatment for two weeks induced finasteride metabolism and reduced its plasma exposure in healthy men.

research Clinical Pharmacokinetics and Pharmacodynamics of Finasteride

93 citations , January 1996 in “Clinical Pharmacokinectics”

Finasteride helps regrow hair and shrink prostate by reducing DHT, with some sexual side effects.

research Finasteride, A Steroid 5α-Reductase Inhibitor, Does Not Affect the Oxidative Metabolism of Antipyrine

9 citations , October 1993 in “The Journal of Clinical Pharmacology”

Finasteride doesn't affect antipyrine metabolism, so interactions with cytochrome P-450 enzyme drugs are unlikely.

research Finasteride: The First 5 Alpha-Reductase Inhibitor

34 citations , July 1993 in “PubMed”

This article reviews the characteristics and uses of finasteride for benign prostatic hyperplasia, noting variable symptom improvement and ongoing investigation in other DHT-mediated conditions, and reports no new clinical results.