Home Patients Clinicians Links

Herbal Medications and Hepatotoxicity

by Anne Larson, MD

Standard treatments for chronic hepatitis such as interferon, may not produce lasting benefit and can cause undesirable side effects. Subsequently, there has been an explosion of interest in the use of herbal medications in the past few years. These products are heavily promoted in the lay press and widely available through health food stores and pharmacies. In the United States, 34% of adults report the use of unconventional therapies and 3% use herbal preparations on a regular basis; however, the true incidence and prevalence of use of herbal preparations is probably higher.

Most physicians are not educated about alternative remedies and are often uncomfortable discussing them. The most frequent recommendation given is to avoid them altogether. Many patients consider "natural" herbal remedies to be safe and completely free of unwanted side effects. While some herbal preparations, such as mild thistle (silymarin), are probably safe, many "natural" plant products are frankly toxic. Herbal remedies, including teas, powders, tablets, and capsules, are not regulated by either state or federal agencies, and safety and efficacy studies have not been performed. Furthermore, there are often discrepancies between the ingredients listed on the label and the actual contents of the preparation (this is especially true of the Chinese preparations). It can frequently be difficult to identify the agent actually responsible for the hepatotoxicity when it occurs.

A number of recent reports of have emphasized the potential for hepatic injury relating to the use of herbal products. Hepatotoxicity has been reported following the use of the Chinese herbal tea Jin Bu Huan (Lycopodium serratum), the Chinese herbal product Ma Huang, germander (Teucrium chamaedrys), valerian, mistletoe, skullcap, chaparral leaf (Larrea tridentata), comfrey tea (Symphytium sp.), other herbal teas containing toxic alkaloids, and pennyroyal oil.

Our recommendations to patients are based on the currently available literature:

  1. "Natural" isn't always safe. While natural herbal remedies are considered safe by patients, we emphasize the point that many "natural" compounds are dangerous when ingested and may do more harm than good. Even beneficial plants can be dangerous when taken at higher doses. There are no intrinsically good chemicals, regardless of their origin.
  2. Mega-doses should be avoided. Even certain vitamins are toxic when taken in large dosages. Stick to the prescribed dose and, remember, everything in moderation!
  3. Communication is important. Encourage the patient to inform their doctors about all compounds they are taking. While we may not approve, we can help educate the patient (and perhaps ourselves!). We can also monitor more closely for signs of toxicity.
  4. In the setting of liver disease, even "safe" herbal remedies may worsen the picture. There are many reports of liver toxicity from herbs that have been prescribed to "help" the sick liver, including complete destruction of the organ necessitating transplantation. May of the "liver purifying" elixirs are made with alcohol!
  5. Patients often feel that traditional doctors are "suppressing" herbal remedies. MDs don't recommend herbal treatments because most of them have not been adequately studied. This is how we are trained to practice medicine. It helps the patient to understand this.
  6. Encourage the patient to continue to seek conventional medical care as well. It would be a shame if the patient missed out on an effective treatment because they assume herbal remedies can replace traditional medications.


©Copyright 2000   University of Washington. All rights reserved