Heartleaf Houttuynia — Safety & Interactions

Yu Xing Cao · Herba Houttuyniae

Contraindications

  • Cold-Damp Lung patterns (cough with clear-white phlegm, no fever)
  • Spleen-Stomach Deficiency Cold

Cautions

  • Standard dose 15–30g fresh herb or 15–25g dried in decoction; add in final 5 minutes to preserve volatile houttuynin
  • Aristolactams A and B are present at low levels; aristolochic acids (the nephrotoxic compounds) are absent or below detection — avoid prolonged unsupervised use as precaution
  • Injectable preparations (sodium houttuyfonate injection) were suspended nationally in China in 2006 following serious allergic reactions; injectable form is NOT equivalent to oral/decoction safety profile
  • Oral and topical use considered safe at standard doses based on centuries of use

Drug Interactions

Drug Class / Substrate Mechanism Severity Source
Anticoagulants / antiplatelet drugs: possible additive blood-thinning effect due to quercetin content; monitor for increased bleeding risk
Immunosuppressants: potential additive immunomodulatory effect; caution in transplant patients or those on immunosuppressive therapy

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.