Herbal medicine drug interactions

From Ganfyd

Well described are:^[1]

• Danshen (Salvia miltiorrhiza)
  • Enhanced anticoagulation with warfarin^[2]
• Garlic (Allium sativum)
  • Interacts with paracetamol metabolism
  • Alters metabolism of
    • warfarin (no definite clinical reports)
    • saquinavir
  • Hypoglycaemia with chlorpropamide
• Ginkgo (Ginkgo biloba)
  • Bleeding with warfarin
  • Hypertension with thiazides
  • Coma with trazodone
• Ginseng (Panax ginseng)
  • Increases metabolism of:
    • Alcohol(not significant in man)
    • Warfarin
  • Mania with phenelzine.
• Kava (Piper methysticum)
  • Increases 'off' periods in Parkinson's with levodopa
  • Coma with alprazolam
• Piperine (Black pepper -Piper nigrum. long pepper -P. longum)
  • rifamipicin concentrations enhanced
• St John's wort (Hypericum perforatum)
  • Increases metabolism of:
    • Ciclosporin(led to organ rejection)
    • Amitriptyline
    • Digoxin
    • Amprenavir, indonavir, lopinavir, ritonavir and saquinavir
    • Warfarin
    • Theophylline
    • Benzodiazepines
  • Unwanted pregnancies and intermenstrual bleeding if taken with oral contraceptives (ethinylestradiol/desogestrel)
  • Delirium with loperamide
  • Serotonin syndrome with selective serotonin-reuptake inhibitors (sertaline, paroxetine, nefazodone)
  • Hypericin component increases cortisol metabolism^[3]

References

External Links

• NLH Q&A Service. A question about warfarin and herbal remedies. Includes a reference to:
• Herbal Remedies: Adverse Effects and Drug Interactions American Family Physician