Herbal side effects and drug interactions

By Rob Wulforst


Last weekend, I attended several seminars in Florida, which I enjoy immensely.  I was also honored to present one myself.  One of the seminars I attended had to do with Chinese herbs and I wanted to talk about something that was only touched upon, herbal side effects and drug interactions.

The Herbal 101 seminar explained the TCM characteristics of the herbs and how they interact with the body.  The presenter also gave examples with some of the more common herbs found in our daily coming and goings. In the end, someone came up and spoke about how the herbs are very safe and how they’re better to take every day then chemically altered pills.

While I agree with this to a point, some TCM herbs themselves also have side effects.  These side effects, known as toxicity, generally start to affect the body when taken at certain dosages. For example, Xì Xīn (細辛) at 9 grams, which doesn’t seem like much, can start to cause toxicity symptoms.  This concept shouldn’t be a surprise though.  Certain vitamins, such as A and D, can cause toxicity if too much is taken daily.  

Herbal formulas can also have interactions with medical prescriptions.  For example, Táo Hóng Sì Wù Tāng is not safe to take while on blood thinners, such as Warfarin/Coumadin.  Therefore, it’s always best to talk to your doctor and your OM practitioner about any medications you’re currently taking or any medical problems you’ve had in the past.  This will help them help you better.

I was discussing the seminar afterwards with a few colleagues of mine and I was reminded of a story my mentor told me.  He had given an herbal formula to a patient who had Qi Deficiency (which would equate to a kind of muscle and body weakness) and the patient came back to him to ask why he had given him Gān Căo (Licorice root - 甘草).  The patient explained he looked up all the herbs in the formula and saw that licorice can cause vasoconstriction of the blood vessels.  So, my mentor was accused that his “mistake” in the formula could potentially cause the patient to have a heart attack, as he had high blood pressure.

Licorice does cause vasoconstriction as a side effect, but only at very high dosages.  A typical dosage of licorice used in a formula is usually anywhere between 3 to 6 grams per day.  Side effects for licorice would normally start somewhere around 30 – 60 grams per day.  However, it took some time to explain this to the patient, which is understandable.  None of us want to worry whether or not what we’re taking is hurting us.

While I agree that herbal medicine is “safe”, it is only when used properly. The same goes with medical prescriptions.  Be sure to do your research about them and ask questions if you have any concerns.  Some years ago, I remember going over my grandfather’s medication with him.  He was prescribed new pills for his high blood pressure and dizziness, and he wanted my opinion on them. Funny enough, the side effect of his dizziness medications was dizziness. It does not make sense but that's very common in western medicine. So do your research, ask questions, and use common sense to minimize possible side effects and drug interactions.