The C.A.M. Report
Complementary and Alternative Medicine: Fair, Balanced, and to the Point
  • About this web log

    This blog is intended as an objective and dispassionate source of information on the latest CAM research. Since my background is in pharmacy and allopathic medicine, I view all CAM as advancing through the development pipeline to eventually become integrated into mainstream medical practice. Some will succeed while others fail. But all are treated fairly here.

  • About the author

    John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at www.Vicus.com, a complementary and alternative medicine website.

  • Common sense considerations

    The material on this weblog is for informational purposes. It is not medical advice or counsel. Be smart, consult your health professional before using CAM.

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  • Recent Comments

    Potential for licorice-drug interactions

    Glycyrrhizin is a major ingredient of licorice, which is sometimes used in the treatment of various diseases such as chronic hepatitis.

    In animals, licorice or glycyrrhizin alters the activity of the CYP3A drug-metabolizing enzyme. Researchers at Central South University, in Hunan, People’s Republic of China looked for an effect in people.

    First, the details.

    • 16 healthy adult men were assigned to take each treatment in different order.
      • Placebo or glycyrrhizin for 14 days.
    • On the 15th day, the benzodiazepine-type drug midazolam (Versed) was administered and blood samples were obtained to determine midazolam concentrations.

    And, the results.

    • The area under the concentration-time curve (AUC; a measure of total drug uptake into the body) was about 5% greater after placebo than midazolam.

    The bottom line?

    The authors concluded, “Administration of glycyrrhizin resulted in a modest induction of CYP3A.”

    In other words, there is the potential that taking licorice decreases the response to midazolam.

    In another study, the same researchers reported that glycyrrhizin stimulates the CYP3A4 enzyme to metabolize the anti-ulcer drug omeprazole (Prilosec) faster, which resulted in lower omeprazole blood levels.

    Another study in animals suggests there may be a similar effect when glycyrrhizin is taken with methotrexate (Rheumatrex).

    It’s important to consider that cytochrome P450 3A (CYP3A) is involved in the biotransformation of more than half of all drugs currently available. Even based on the limited data reported in the 3 studies above, it would be prudent to check carefully for the use of licorice in patients who experience a sudden change in their response to drug treatment.

    De-glycyrrhizinated licorice extracts would not be expected to cause these effects because they contain no glycyrrhizin.

    4/20/10 13:27 JR

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