What are the perioperative effects of common herbal medications?

Updated: Mar 16, 2020
  • Author: Robert A Schwartz, MD, MPH; Chief Editor: Dirk M Elston, MD  more...
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An enormous public enthusiasm exists for herbal medications. Herbal medications are widely used among the presurgical population. Morbidity and mortality associated with herbal medications may be more likely in the perioperative period because of the polypharmacy and the physiological alterations that occur. Such complications include myocardial infarction, stroke, bleeding, inadequate oral anticoagulation, prolonged or inadequate anesthesia, organ transplant rejection, and interference with medications indispensable for patient care.

In 1997, approximately 12% of the US population used herbal medications; this rate represents a 380% increase from 1990. Patients undergoing surgery appear to use herbal medications more frequently than the general population. [15] For instance, Tsen et al reported that 22% of patients who underwent evaluation in their preoperative clinic took herbal medications. [16] Kaye et al found that 32% of patients in an ambulatory surgical setting admitted to using herbal medications. [17] More than 22.8 million Americans use herbs instead of prescription medications, and 30 million Americans use herbal medication instead of over-the-counter medications. A study sampling 601 parents found that 16.6% of children have used or currently use herbal medications. A positive correlation exists between parental use and children use of herbal medication. [18]

In the study by Kaye et al, more than 70% of patients failed to disclose their herbal medicine use during routine preoperative assessment. [17] Explanations for this lack of disclosure include patient-held beliefs that physicians are not knowledgeable about herbal medications or that they are prejudiced against herbal use. In addition, some patients fear to admit their use of unconventional therapies to their physician. Others may neglect to mention that they are taking herbal medications because they are using them for reasons perceived as unrelated to their medical care. Some patients do not consider herbal substances to be medications, and they consequently neglect to report them during routine preoperative questioning. For these reasons, physicians need to specifically seek out a history of herbal medicine use in patients before surgery.

Despite many uncertainties in commercial preparations, herbal medications adhere to modern pharmacologic principles. A single herbal medication may adversely affect the patient during the perioperative period through a number of different mechanisms. These effects are direct interactions (intrinsic pharmacologic effects), pharmacodynamic interactions (alteration of the action of conventional drugs at effector sites), and pharmacokinetic interactions (alteration of the absorption, distribution, metabolism, and elimination of conventional drugs). [19]

Eight commonly used herbal medications are echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John's wort, and valerian. These herbs account for more than 50% of all single-herb preparations among the 1500-1800 herbal medications sold in the United States.

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