CURBICIN INTERACTION WITH WARFARIN (Coumadin, Jantoven)

Curbucin is the preparation of saw palmetto, pumpkin, and vitamin E².  It is commonly used for micturition difficulties and benign prostatic hyperplasia².   The active ingredients are extracted from the fruit of Serenoa repens and the seed of Cucurbita pepo.  Concurrent administration of warfarin (Coumadin, Jantoven) and Curbicin may increase the anticoagulant effect of warfarin (Coumadin, Jantoven).  The possible mechanism of action is that vitamin E contained in Curbicin (10mg/tablet) can antagonize the effect of vitamin K on coagulation. Hence, it may increase the risk of bleeding in patients taking oral anticoagulants. 

There have been two case studies for this interaction¹. 

-         A 73-year-old man with a common cold, who had been taking Curbicin three tablets daily for more than one year, developed a coagulation disorder with an INR = 2.1 despite a normal albumin concentration and no anticoagulant treatment.  His INR improved to 1.4 with vitamin K, but was not normalized until Curbicin was withdrawn 1 week later.

-         A 61-year-old man, who had taken warfarin (Coumadin, Jantoven) and simvastatin for a long time, and had an INR of 2.4, started to take Curbicin five tablets daily for trouble getting a stream of urine flowing..  After 6 days his INR had increased to 3.4. After withdrawal of Curbicin the INR returned to previous value within 1 week. 

The two cases suggest that caution is necessary when Curbicin is used concurrently with warfarin (Coumadin, Jantoven) to avoid any bleeding events.

 

References:

1. Yue QY, Jansson K. Herbal Drug Curbicin and Anticoagulant Effect with and without warfarin  Possible Related to the Vitamin E Component. J An Geriatr Soc 2001; 49: 838.
2. Izzo A et el. Cardiovascular Pharmacotherapy and Herbal Medicines: The Risk of Drug Interaction. Int J of Cardiology 2005 ; 98: 1-14

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