Extracts from this woody plant are injected or infused for cancer treatment, often reducing side effects and improving quality of life, and perhaps improving survival.
Safety and precautions
We at CancerChoices strongly advise anyone thinking about using mistletoe to consult a physician knowledgeable and experienced in its use to prescribe it and monitor your response.
Common side effects are typically mild but can depend on the dose.1Mistletoe (Viscum album). Centre for Health Innovation. February 2024. Viewed May 28, 2024;; Horneber MA, Bueschel G, Huber R, Linde K, Rostock M. Mistletoe therapy in oncology. Cochrane Database of Systematic Reviews. 2008 Apr 16;(2):CD003297.
Several cautions, contraindications, adverse events, and herb-drug interactions are described in the Centre for Health Innovation monograph, Mistletoe (Viscum album):
Subcutaneous injections: injection site reactions (redness, swelling, itching), fatigue, flu-like symptoms, mild fever, diarrhea, and headache. Severe local reactions at the injection site occur in fewer than 1% of people.
Intravenous infusions: mild fever, itching, weakness, fatigue, re-inflammation of prior injection sites.
Serious reactions are rare but include these:
- Severe, potentially life-threatening allergic or pseudo-allergic reactions (anaphylaxis)
- Swelling of throat, skin and mucous membranes (angioedema)
- Low blood pressure (hypotension)
- Loss of consciousness
- Skin infection (cellulitis) at the injection site
Side effects or adverse events
Incidence and severity of side effects from subcutaneous mistletoe use are reported in a 2014 study. The most common:2Steele ML, Axtner J et al. Adverse drug reactions and expected effects to therapy with subcutaneous mistletoe extracts (Viscum album L.) in cancer patients. Evidence-Based Complementary and Alternative Medicine. 2014;2014:724258.
- Fever
- Local reaction
- Hives (urticaria)
- Injection site redness of the skin (erythema)
- Chills
A few people with high-risk malignant melanoma experienced adverse drug reactions, requiring therapy termination in fewer than 2% of patients receiving mistletoe.3Augustin M, Bock PR, Hanisch J, Karasmann M, Schneider B. Safety and efficacy of the long-term adjuvant treatment of primary intermediate- to high-risk malignant melanoma (UICC/AJCC stage II and III) with a standardized fermented European mistletoe (Viscum album L.) extract. Results from a multicenter, comparative, epidemiological cohort study in Germany and Switzerland. Arzneimittelforschung. 2005;55(1):38-49.
A few cases of anaphylactic shock have been reported with use.4Hutt N, Kopferschmitt-Kubler M et al. Anaphylactic reactions after therapeutic injection of mistletoe (Viscum album L.). Allergologia et Immunopathologia (Madr). 2001 Sep-Oct;29(5):201-3. Higher doses of mistletoe (2000 mg pine-mistletoe extract or 4800 or greater ng/kg of mistletoe lectins), particularly given intravenously or intratumorally, increase risk for allergic or pseudo-allergic reactions, fever, and other side effects.5Huber R, Schlodder D, Effertz C, Rieger S, Tröger W. Safety of intravenously applied mistletoe extract—results from a phase I dose escalation study in patients with advanced cancer. BMC Complementary and Alternative Medicine. 2017 Sep 18;17(1):465; Kienle GS, Grugel R, Kiene H. Safety of higher dosages of Viscum album L. in animals and humans–systematic review of immune changes and safety parameters. BMC Complementary and Alternative Medicine. 2011 Aug 28;11:72; Hutt N, Kopferschmitt-Kubler M et al. Anaphylactic reactions after therapeutic injection of mistletoe (Viscum album L.). Allergologia et Immunopathologia (Madrid). 2001 Sep-Oct;29(5):201-3.
Do not use (contraindications)
According to Neil McKinney, ND, mistletoe should not be used with a fever greater than 100.4°F (38°C), nor with abdominal fluid (ascites) or with brain tumors or other tumors in tight compartments where an immune response can cause initial inflammatory swelling (edema) and subsequent compression of vital structures.6McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016.
Dr. McKinney says mistletoe may activate a hidden focus of infection, such as dental abscess. He also cautions that increased cytokine release may aggravate wasting (cachexia). He considers mistletoe to be contraindicated in pregnancy, breastfeeding, tuberculosis, biliary stenosis, liver failure, heart failure, kidney failure, hyperthyroidism, and with interferon or interleukin therapies.7McKinney N. Naturopathic Oncology, Fourth Edition. Victoria, BC, Canada: Liaison Press. 2020.
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