MEDLINE Journals

    Pharmacokinetic interactions of drugs with St John's wort.

    Authors
    Zhou S, Chan E, Pan SQ, et al. 
    Source
    J Psychopharmacol 2004 Jun; 18(2) :262-76.
    Abstract

    There is a worldwide increasing use of herbs which are often administered in combination with therapeutic drugs, raising the potential for herb-drug interactions. St John's wort (Hypericum perforatum) is one of the most commonly used herbal antidepressants. A literature search was performed using Medline (via Pubmed), Biological Abstracts, Cochrane Library, AMED, PsycINFO and Embase (all from their inception to September 2003) to identify known drug interaction with St John's wort. The available data indicate that St John's wort is a potent inducer of CYP 3A4 and P-glycoprotein (PgP), although it may inhibit or induce other CYPs, depending on the dose, route and duration of administration. Data from human studies and case reports indicate that St John's wort decreased the blood concentrations of amitriptyline, cyclosporine, digoxin, fexofenadine, indinavir, methadone, midazolam, nevirapine, phenprocoumon, simvastatin, tacrolimus, theophylline and warfarin, whereas it did not alter the pharmacokinetics of carbamazepine, dextromethorphan, mycophenolic acid and pravastatin. St John's wort decreased the plasma concentration of the active metabolite SN-38 in cancer patients receiving irinotecan treatment. St John's wort did not alter the pharmacokinetics of tolbutamide, but increased the incidence of hypoglycaemia. Several cases have been reported that St John's wort decreased cyclosporine blood concentration leading to organ rejection. St John's wort caused breakthrough bleeding and unplanned pregnancies when used concomitantly with oral contraceptives. It also caused serotonin syndrome when coadministered with selective serotonin-reuptake inhibitors (e.g. sertaline and paroxetine). Both pharmacokinetic and pharmacodynamic components may play a role in these interactions. Because the potential interaction of St John's wort with other drugs is a major safety concern, additional systematic research on herb-drug interactions and appropriate regulation in herbal safety and efficacy is needed.

    Mesh
    Administration, Oral
    Animals
    Cytochrome P-450 CYP3A
    Cytochrome P-450 Enzyme System
    Enzyme Induction
    Herb-Drug Interactions
    Humans
    Hypericum
    P-Glycoprotein
    Plant Preparations
    Randomized Controlled Trials as Topic
    Language

    eng

    Pub Type(s)
    Journal Article Research Support, Non-U.S. Gov't Review
    PubMed ID

    15260917

    Content Manager
    Related Content

    Herb-drug interactions: a literature review.

    The emerging recognition of herb-drug interactions with a focus on St. John's wort (Hypericum perforatum).

    Clinical drugs that interact with St. John's wort and implication in drug development.

    Interactions between herbal medicines and prescribed drugs: an updated systematic review.

    Drug interactions with St. John's Wort (Hypericum perforatum): a review of the clinical evidence.

    The effects of St John's wort (Hypericum perforatum) on human cytochrome P450 activity.

    Interactions between herbal medicines and prescribed drugs: a systematic review.

    The interaction between St John's wort and an oral contraceptive.