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

November 2008 in “ European Journal of Pharmaceutical Sciences ”

Anna Lundahl, Mikael Hedeland, Ulf Bondesson, Lars Knutson, Hans Lennernäs

St. John's wort finasteride pharmacokinetics metabolism biliary excretion plasma concentration elimination half-life urinary excretion Propecia SJW

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

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This study investigated the effect of St. John's wort on the pharmacokinetics, metabolism, and biliary excretion of finasteride and its metabolites in healthy men. The results showed that SJW treatment significantly reduced the peak plasma concentration, the area under the plasma concentration-time curve, and the elimination half-life of finasteride. The biliary and urinary excretion of the drug and its metabolites were also affected. The study concluded that SJW treatment induced the metabolism of finasteride and caused a reduced plasma exposure of the drug. Therefore, caution should be exercised when using St. John's wort in combination with finasteride.

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

Research cited in this study

research The Effect of Finasteride on the Risk of Acute Urinary Retention and the Need for Surgical Treatment Among Men with Benign Prostatic Hyperplasia

research Clinical Pharmacokinetics and Pharmacodynamics of Finasteride

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

research Finasteride: The First 5α-Reductase Inhibitor

research Finasteride: A Slow-Binding 5-Alpha-Reductase Inhibitor

research The Effect of Finasteride in Men with Benign Prostatic Hyperplasia

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