Clinical Trial: Evaulation of Interaction Between Herbal Products and Anticoagulants

This study is not yet open for patient recruitment.

Sponsored by: National Center for Complementary and Alternative Medicine (NCCAM)
Information provided by: National Center for Complementary and Alternative Medicine (NCCAM)


The purpose of this study is to determine if the use of herbal products interferes with normal anticoagulation, leading to either excessive thinning of the blood and bleeding problems or inadequate thinning of the blood and clotting problems. Many patients who are on long term anticoagulation, or blood thinning, for a variety of medical problems, also take herbal products. It is not yet known whether use of herbal products interferes with this anticoagulation, and puts patients at risk for bleeding or clotting. This study will carefully monitor patients who are taking herbs and anticoagulants to determine if their laboratory tests show signs of being affected by the herbs. The study will ask all patients about their herbal product use, so all reported herbs will be included and monitored.

control of anticoagulation

MedlinePlus consumer health information 

Study Type: Observational
Study Design: Natural History, Longitudinal, Defined Population, Prospective Study

Official Title: Early Identification of Adverse Reactions to Herbs

Further Study Details: 

Expected Total Enrollment:  2000

Study start: January 2006;  Expected completion: December 2007


Ages Eligible for Study:  18 Years and above,  Genders Eligible for Study:  Both

Accepts Healthy Volunteers


Inclusion criteria:

  • Taking longer-term (>6 months) anticoagulation
  • Enrolled in one of Kaiser Permanente Northern California anticoagulation clinics

Location Information

      Kaiser Permanente, Northern California, Oakland,  California,  United States

Study chairs or principal investigators

Stephen Bent, MD,  Principal Investigator,  University of California, San Francisco   

More Information

Study ID Numbers:  K08 AT001338-01
Record last reviewed:  December 2004
Last Updated:  December 13, 2004
Record first received:  October 29, 2003 Identifier:  NCT00071682
Health Authority: United States: Federal Government processed this record on 2005-04-08

Cache Date: April 9, 2005