Danshen: A Popular Chinese Cardiac Herbal Drug

The recently published document in JACCon complementary and integrative medicine (1) left out one very important herbal drug, danshen. Because it is believed to have properties of improving microcirculation, increasing coronary blood flow, suppressing thromboxane formation, inhibiting platelet adhesion and aggregation, and protecting against myocardial ischemia (2), it is used either alone or in combination with other herbal ingredients for patients with coronary artery disease (CAD), in both China and other countries, including the U.S.

Conversely, danshen also interacts with warfarin by potentiating its anticoagulant action (3). Because both warfarin usage and CAD are so common in everyday cardiologic practice, the possibility of the interaction between warfarin and danshen should be kept in mind when excessive bleeding or unexpected prolongation of the prothrombin time or international normalized ratio is encountered in any patient on warfarin who has otherwise been under good anticoagulant control. Because danshen is a common compound of many cardiotonic herbal preparations, patients oftentimes may not be aware that they are actually taking it. Furthermore, danshen can be administered not only as an oral tablet but also in a nebulizer (4). It has even been incorporated into some Chinese-brand cigarettes (5), so that many cigarette smokers may not even be aware of its presence.

• American College of Cardiology Foundation