Warfarin Dong quai

Dong quai Warfarin Dong quai contains coumarin... 

Dong quai Warfarin Increased anticoagulant effect of warfarin bleeding... 

Dong quai No demonstrated efficacy Not recommended Structurally similar to coumarins—avoid with warfarin because INR can increase... 

Dose Initial 0.25 mg PO tid, wkly 10.25 mg/dose, to 3 mg max max 4 mg for RLS Caution [C, /-] Sev e CV, renal, or hepatic impair Contra Component allergy Disp Tabs SE Syncope, postural X BP, NA, HA, somnolence, dosed-related hallucinations, dyskinesias, dizziness Interactions t Risk of bleeding W/ ASA, NSAIDs, fevCTfew, garlic, ginger, horse chestnut, red clover, EtOH, tobacco t effects OF amitriptyline, Li, MTX, theophylline, warfarin t risk of photosensitivity W/ dong quai— use sunscreen, St. John s wort X effects W/ antacids, rifampin X effects OF ACEIs, diuretics EMS t Bleeding risk w/ concurrent EtOH, tobacco, ASA, and NSAID use t effects of warfarin OD May cause N/V, drowsiness, hypotension, and CP symptomatic and supportive... 

Page RL II, Lawerence JD. Potentiation of warfarin by dong quai. Pharmacotherapy 1999 19 870-878. 

CHINESE BOTANICAL PRODUCTS AND WARFARIN Angelica sinensis (Chinese Angelica, Dong Quai)... 

Warfarin Dong quai (Angelica sinensis) Increased INR and widespread bruising Dong quai contains coumarins... 

A 46-yr-old black female experienced an increase in INR from 2-3 to 4.05-4.9 after taking 565 mg of dong quai once or twice daily for 4 wk. The patient s past medical history included rheumatic heart disease, stroke, and atrial fibrillation. Medications included 5 mg/d of warfarin, 0.25 mg/d of digoxin, and 20 mg/d of furosemide. Upon dechallenge from dong quai, her... 

Two case reports describe a very marked increase in the anticoagulant effects of warfarin when dong quai was given. 

These seem to be only reports of this apparent interaction, but patients taking warfarin should be warned of the potential risks of also taking dong quai. For safety dong quai should be avoided unless the effects on anticoagulation can be monitored. More study is needed. 

Human case reports and an animal study have indicated a possible interaction between warfarin and dong quai (Ellis and Stephens 1999 Lo et al. 1995 Page and Lawrence 1999). 

In rabbits orally administered 4 g/kg daily dong quai and subcutaneously administered warfarin, an increase in prothrombin time was observed in a steady-state model of warfarin administration, whereas in a single-dose model, no significant changes in prothrombin time were observed. Dong quai alone did not produce any changes in prothrombin time (Lo et al. 1995). 

---