Green Tea

1. Precautions
   1. Green Tea is safe, but NOT Green Tea extract
   2. Avoid Green Tea extract (risk of liver toxicity)
2. Indications: Topical
   1. Genital and Perinanal Warts (Sinecatechins or Veregen 15% is FDA approved)
3. Indications: Oral
   1. General
      1. Conflicting data on benefits
      2. Various forms (capsules, Green Tea beverages)
   2. Potential benefits (requires additional study)
      1. Colorectal Cancer risk reduction
      2. Breast Cancer Risk Reduction
      3. Weight Reduction
      4. Cholesterol reduction
      5. Cardiovascular disease risk reduction
4. Contraindications
   1. Pregnancy (due to theororetical anti-Folate activity)
5. Dosing: Topical (15% Sinecatechins)
   1. Apply 0.5 cm per wart three times daily for 16 weeks
6. Dosing: Oral
   1. Typical dose: 3 cups Green Tea per day (~320 mg Polyphenols)
   2. Most studies used between 3-5 cups/day of Green Tea
7. Adverse Effects: Topical
   1. Contact reaction (allergic or irritant)
8. Adverse Effects: Oral
   1. Gastrointestinal upset
   2. Hepatotoxicity (case reports)
9. Drug Interactions: General
   1. Warfarin
      1. Possible Warfarin antagonist at high dose (due to Vitamin K)
10. Drug Interactions: OATP Inhibitor (Organic anion-transporting polypeptide inhibitor)
    1. Background
       1. Orange juice, apple juice and Grapefruit juice also inhibit the OATP transporter
       2. Catechins in Green Tea also inhibits the OATP transporter
       3. Green Tea 12 oz twice daily may have a Clinically Significant effect
    2. Medications affected
       1. Atenolol
       2. Nadolol
       3. Ciprofloxacin
       4. Levofloxacin
       5. Levothyroxine
       6. Statins
       7. Imatinib (Gleevac)
       8. Antiretrovirals
    3. References
       1. (2014) Presc lett 21(3)
11. References
    1. Asher (2017) Am Fam Physician 96(2): 101-7 [PubMed]
    2. Cabrera (2006) J Am Coll Nutr 25: 79-99 [PubMed]
    3. Schneider (2009) Am Fam Physician 79(7): 591-4 [PubMed]