Updates on the Clinical Evidenced Herb-Warfarin Interactions

Table 3

Summary of herb-warfarin interactions supported by clinical evidence.

Herbs; (common and Latin name)	Clinical effects	Severity	Reliabilities of evidence	Mechanisms
				PK	PD
Cranberry; (Vaccinium macrocarpon)	Potentiation	Major [55]	I	F [52, 53, 160]	D [40]
Soya; (Glycine max Merr.)	Inhibition	Moderate [115, 116]	I	F [113, 114]	B [115]
St John’s wort; (Hypericum perforatum)	Inhibition	Major [121, 122]	I	F [41, 118, 119]	NA
Danshen; (Salvia miltiorrhiza)	Inhibition	Moderate [133, 134]	I	F, G [131, 132, 135, 136]	A,C [40]
Coenzyme Q10; (Theobroma cacao)	Inhibition	Minor [47, 48]	II	NA	B [50]
Chinese angelica; (Angelica sinensis)	Potentiation	Moderate [126]	II	F [125]	C [40]
Ginger; (Zingiber officinale Roscoe)	Potentiation	Moderate [161]	II	NA	A [162]
Chamomile; (Matricaria recutita)	Potentiation	Major [44]	III	F [41, 163, 164]	NA
Chitosan; (Swertia chirayita)	Potentiation	Moderate [46]	III	NA	B [45]
Cannabis; (Cannabis sativa L)	Potentiation	Major [165]	III	F [166]	NA
Devil’s claw; (Harpagophytum procumbens)	Potentiation	Moderate [61]	III	F [60]	NA
Ginkgo; (Ginkgo biloba)	Potentiation	Major [83]	III	F [75–77]	NA
Garlic; (Allium sativum)	Potentiation	Major [40]	III	F [167, 168]	A [73, 169]
Ginseng; (Panax quinquefolius/Panax ginseng)	Inhibition	Moderate [170]	III	F [40]	A [87]
Grapefruit; (Citrus paradise)	Potentiation	Major [94]	III	F [95]	NA
Green tea; (Camellia sinensis)	Inhibition	Moderate [97]	III	NA	B [99]
Lycium; (Lycium barbarum)	Potentiation	Major [139]	III	F [137]	NA
Boldo; (Peumus boldus)	Potentiation	Minor [36]	IV	NA	C [40]
Echinacea; (Echinacea purpurea)	Inhibition	Minor [66]	IV	F [119, 171]	NA
Fenugreek; (Trigonella foenum-graecum)	Potentiation	Minor [36]	IV	NA	B, C [40]
Melilot; (Melilotus officinalis)	Potentiation	Moderate [102]	IV	NA	C [40]
Parsley; (Petroselinum crispum)	Potentiation	Moderate [104]	IV	F [103]	B [40]
Pumpkin; (Cucurbita pepo)	Potentiation	Minor [106]	IV	NA	B [40]
Red clover; (Trifolium pretense)	Potentiation	Major [108]	IV	F [60, 107]	NA
Saw palmetto; (Serenoa repens)	Potentiation	Minor [106, 111]	IV	F [109]	NA

Notes. (1) As to mechanisms of herb-warfarin interaction, PD factors including the following: A: interference with platelet function; B: altering gut vitamin K synthesis or containing vitamin K; C: interference with vitamin K cycle; D: interference with coagulation cascade. PK factors including the following: E: interference with warfarin absorption; F: interference with metabolizing enzymes of warfarin; G: interference with protein binding of warfarin. (2) Other nonclinical evidenced herbs defined as doubtful in Section 3 were excluded in this table.