A Quick Look at How Drug-Herb Interaction is Studied
When looking at drug-herb interaction, researchers tend to focus more on the drug side of things; this is because drugs are very specific lab-made synthetic compounds, whereas herbs are complex organisms (for the most part). Drugs are essentially a chemical equation with every action accounted for in their structures. Herbs are latticework of organic structures which have naturally evolved, so, frankly, it's too difficult to isolate specific properties to study.
With that in mind, the basic approach is to take any given drug and ask whether or not it's properties allow it to be safely combined with other things including herbs, supplements, foods, and other drugs. The main way of deciding this is looking at the drug's therapeutic index - the window in which a drug works both safely and effectively. If a drug has a wide therapeutic index, there's less of a concern that other things in the body can render it ineffective or dangerous. If a drug has a narrow therapeutic index, there is very little difference between a safe dosage and a toxic dosage, so there is a greater concern about interfering with its actions.
Prescribing Chinese Herbs Safely
There are several steps we take to make sure that it is safe for our patients to take an herbal formula whether they are taking prescription medications or not:
1) Extensive study and training of Chinese herbal medicine. We spend 4 years learning the herbs inside and out. We are trained to identify the herbs by sight, smell, and taste, must know their actions on the body and what parts of the body they act on, what symptoms and conditions they treat, how to combine them into formula, how to prepare and cook them, and all possible contraindications. As acupuncturists, we are often compared to doctors, but when it comes to herbal knowledge, we are more like pharmacists.
2) Detailed diagnosis. With any system of medicine, treatment is only safe and effective when you nail the diagnosis. This is the most emphasized aspect of Chinese medicine, and herbs are only ever prescribed in accordance with a Chinese medicine pattern diagnosis.
3) Dosing low. This is something we do at Meridian as an extra precaution. Because people are generally not used to drinking teas made from twigs and barks, and because people are used to supplements working very subtly over time, we always start with the lowest effective dosage and increase it as needed. This is how herbal medicine is practiced in Japan, as well. Like the Japanese, Americans seem to have more delicate systems than the Chinese. In China, patients regularly leave the hospital with their raw herbs for the week in dosages that fit in garbage bags. What we give patients as a weekly dose, Chinese herbalists prescribe and package for daily consumption. Keep in mind that this is in conjunction with pharmaceutical medications, as well!
Each one of these is one day's dose. |
4) Constant monitoring. We prefer to prescribe herbs one week at a time and have patients report back to us before refilling their formulas. This allows us to make adjustments in ingredients and dosages based on changes in symptomology. This allows helps us determine when herbs are no longer needed. Most patients are on herbs temporarily, though it may be long-term. This is in stark contrast to drugs which many patients are on indefinitely.
5) Caution with herbs with similar actions as drugs. On one hand, a formula that supports and enhances the action of meds can be very useful. In fact, many patients, in consultation with their physicians, are able to reduce or come off their meds while taking herbs. It serves as a natural way to ween off of pharmaceuticals. Again, those decisions are made by patients and their doctors rather than us. On the other hand, increasing the action of specific drugs can be non-therapautic. For example, if someone is on blood thinners, we are careful about using herbs which also invigorate the Blood from a TCM perspective. While even that is usually safe, we always operate with an abundance of caution.
6) Avoiding harsh herbs in conjunction with hardcore drugs. This goes back to the idea of therapeutic index. Most of the drugs that have a narrow therapeutic index are very serious meds like lithium and certain type of chemotherapy drugs. It is very rare that these patients also present with a condition that would required our harsher herbs (things like aconite or scorpion, which in large enough dosages can be slightly toxic). We are extremely cautious when these things show up on the med lists, and sometimes the safest and most appropriate course is to forego herbs altogether.
Following these principles, we have never had a problem with bad reactions from herbal formulas. At this point we've prescribed formulas to thousands of patients, most of whom have been on some form of prescription drugs. Even when advising patients that they might get a bit of an upset stomach the first day (since roots and sticks aren't normally in their diet), fewer than 1% ever report experiencing that.
So, are herbs safe to take with prescription drugs? Yes, it can absolutely be done safely, and no patient for which it is not safe will receive herbs!