Dong Quai Interacts with Blood Thinners

While working at a store that primarily sold medicinal herbs, I encountered a woman who was looking for dong quai--an herb also known as Chinese angelica-- as a treatment for menstrual discomforts. She had already reached the check-out line when she turned to me and asked, as an afterthought, "Is it okay to take this with blood thinners?"

I was so shocked that it took me a moment to respond. Anticoagulants, or blood thinners, interact with so many drugs, herbs, supplements and foods that I couldn't believe someone would buy medicinal herbs while taking it, without specifically consulting a physician. This customer's negligence could have led to her own death had I not informed her of the dangers of the interaction.

Coumadin Interactions

Dong quai does interact with blood thinners, and quite dangerously. Warfarin, or Coumadin, is used to slow blood clotting. It works by inducing a state similar to vitamin K deficiency. Although this can help to prevent blood clots, it can also increase the risk of fatal hemorrhagic episodes. For this reason, people taking Coumadin are advised not to use any product that can increase the risk of bleeding. Dong quai is a perfect example of an herb that can not and should not be taken with coumadin.

Dong Quai and Bleeding

Historically, dong quai has been used as a treatment for amenorrhea, or an absence of menstruation. At one point, Western herbalists attributed this effect to hormone-like compounds in the herb. We now know that dong quai actually increases bloodflow to the uterus and thins the blood around reproductive organs. This causes menstruation to begin, and to be heavier than usual. These anticoagulant effects are the precise reason for the blood thinner drug interaction. It could dangerously amplify the effects of the drug.

A Fatal Interaction

The drug-herb interaction between blood thinners and dong quai could be life-threatening. In its most mild form, it might lead to a few extra bruises, bleeding gums, or a nose bleed. In other cases, it could be a fatal mistake. Coumadin combined with dong quai could trigger bleeding in the brain (a hemorrhagic stroke), bleeding in the colon, or internal hemorrhage after a minor accident. Although there are no reported deaths from this interaction, it is not an improbable outcome if someone combined the two products.

Other Interactions

Dong quai does not interact with coumadin alone; it could cause similar, serious side effects in people using any other products with anticoagulant effects. Common pain-relieving drugs, known as nonsteroidal anti-inflammatories (NSAIDs), also create this effect. Aspirin, Plavix, Voltaren, ibuprofen, naproxen, Fragmin, Lovenox, and heparin could all interact fatally with dong quai. Additionally, dong quai interacts with blood-thinning herbs like ginkgo.

Whose Responsibility?

The woman at the store was lucky that I was aware of dong quai's drug interactions. Had I shrugged off her concern, she could have died of the drug-herb combination. However, the knowledge of drug-herb interactions is not the responsibility of a sales associate-- it is the responsibility of the buyer and his or her primary health care provider. Before using any medicinal herb, under any circumstances, it is critical to discuss the risks with a qualified practitioner. Never rely entirely on unaccredited websites, salesmen, or company advertisements as your source of information regarding herb safety. It is your responsibility to take an active role in your health and recovery.

For more information about dong quai, its risks, and its drug interactions, visit the National Institutes of Health.