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Induction of hepatic microsomal enzymes after brief administration of rifampicin in man

J P Miguet, P Mavier, C J Soussy

    Gastroenterology
    |May 1, 1977
    PubMed

    Insights

    Rifampicin administration for six days significantly speeds up drug metabolism in the liver. This induction of the hepatic microsomal drug-metabolizing system may influence drug interactions and toxicity.

    Area of Science:

    • Pharmacology
    • Hepatology
    • Drug Metabolism

    Background:

    • The hepatic microsomal drug-metabolizing system is crucial for drug clearance.
    • Rifampicin is an antibiotic known to affect drug metabolism.
    • Understanding rifampicin's impact on liver enzymes is important for clinical practice.

    Purpose of the Study:

    • To investigate the effect of rifampicin on the human hepatic microsomal drug-metabolizing system.
    • To quantify the induction of liver microsomal metabolism by rifampicin.
    • To assess the implications for drug interactions and potential toxicity.

    Main Methods:

    • Studied 7 patients with normal liver function.
    • Administered oral rifampicin (600 mg/day) for 6 days.
    • Measured plasma disappearance rate and half-life of antipyrine as an index of liver metabolism.

    Main Results:

    • Rifampicin significantly decreased antipyrine half-life from 11.7 ± 4.7 hr to 6.9 ± 2.3 hr.
    • Rifampicin half-life also decreased, indicating self-induction.
    • Demonstrated induction of the microsomal mixed function oxidase system within 6 days.

    Conclusions:

    • Short-term rifampicin administration induces the liver's drug-metabolizing enzymes.
    • This induction may contribute to rifampicin's role in isoniazid hepatotoxicity.
    • Highlights the clinical significance of rifampicin's enzyme-inducing properties.

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