Safety Issues of Herb-Warfarin Interactions

Area of Science:

• Pharmacology and Toxicology
• Herbal Medicine Interactions
• Drug Safety

Background:

• Warfarin is a widely used anticoagulant, but its safety is compromised by interactions with herbs.
• Numerous studies highlight serious adverse events when warfarin is taken with herbal products or formulations.

Purpose of the Study:

• To review the mechanisms of herb-warfarin interactions (HWI).
• To emphasize pharmacokinetic-pharmacodynamic (PKPD) interactions and evidence of HWI in various consumption scenarios.
• To consolidate information on herb-warfarin interactions.

Main Methods:

• A targeted literature review was conducted using various scientific databases.
• Information on herb-warfarin interactions (HWI) was systematically acquired.
• Focus on PKPD interactions and evidence from diverse consumption scenarios.

Main Results:

• Fatal consequences of HWI include bleeding, thrombosis, subarachnoid hemorrhage, and subdural hematomas.
• Specific herbs like *Hypericum perforatum*, *Zingiber officinale*, *Vaccinium oxycoccos*, *Citrus paradisi*, and *Punica granatum* are implicated.
• Herbs such as *Coptis chinensis* and *Phellodendron amurense* compete for plasma protein binding, increasing free warfarin and its antithrombic effect.
• Consumption of *Persea americana* (avocado) can decrease International Normalized Ratio (INR) levels.

Conclusions:

• There is an urgent need for an updated herb-warfarin interaction database.
• Educating patients and healthcare providers on HWI is essential.
• Adopting technologies like natural language processing can aid healthcare professionals in making informed decisions to prevent HWI.