Patients being treated with the blood-thinning drug Coumadin (warfarin) should probably avoid using ginseng, as the popular herb seems to reduce the drug’s effects, new research indicates. Among other indications, Coumadin is often given to patients with an irregular heartbeat called atrial fibrillation to reduce the risk of blood clots and stroke. A blood test called the INR is measured on a regular basis to ensure that the dose being given is not thinning the blood too much or too little.
