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Antioxidants and chemotherapy (pet with hemangiosarcoma)

  • May 9, 2017 2:03 PM EDT

    Question ... Do antioxidants counteract with chemo? We do metronomic chemo for my boy - 16 weeks out from surgery - plus turkey tail, YB, milk thistle, IP6 and k9 immunity. My fear is these meds might work against each other. 

    Answered by Douglas H. Thamm, VMD, DACVIM (Oncology): 

    There is some information in humans that combining antioxidants with certain other conventional forms of therapy like chemotherapy and radiation therapy CAN result in a worsening of the outcome. It is known that some drugs (and radiation) kill cancer cells by generating free radicals inside the cells. Antioxidants lead to decreased free radical production and thus could reduce the effectiveness of the drugs/radiation. Doxorubicin (Adriamycin), the most commonly used drug for hemangiosarcoma, is one of those drugs that act (in part) through free radical generation, so we recommend NOT to give antioxidants to dogs receiving doxorubicin.  

    Unfortunately, we (meaning the veterinary / medical community) don’t know enough about the supplements that your dog is receiving to know if there are any interactions to be concerned about …