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, 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

    Marijuana interaction with warfarin reported

    Researchers from the Cheyenne Veterans Affairs Medical Center, in Wyoming report that when taken together, 1 patient experienced bleeding from the blood “thinner” warfarin (Coumadin).

    First, the details.

    • A 56-year-old man had been treated with warfarin for 11 years after heart valve replacement.
    • He came to the hospital with upper gastrointestinal bleeding.
    • His INR value was very high at 10.41, and his hemoglobin level was low at 6.6 g/dL.
      • The INR test measures the ability of blood clot: normal is 0.8 to 1.2.
      • A normal hemoglobin count is 14-17 g/dL for men.
    • He was treated to control his blood loss and left the hospital after 7 days.
    • 15 days later he returned with a constant nosebleed and increased bruising.
    • His INR value was even higher at 11.55.
    • Again, he was treated.
    • It was learned that the patient smoked marijuana more frequently throughout the period of these 2 hospitalizations due to depression.
    • He was counseled about the potential interaction of warfarin and marijuana.
    • He stopped smoking pot, and during the next 9 months his INR values ranged from 1.08 to 4.40 with no significant bleeding complications.

    The bottom line?
    This is the first reported case of a warfarin-marijuana interaction. More clinical reports would be useful to confirm this interaction.

    A PubMed search since this research was published revealed nothing new on this topic.

    6/17/09 19:08 JR; 2/3/11 21:52 JR

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