Study says patients can take some herbs until 24 hours before surgery

But ASA advises discontinuing use at least two weeks before procedure

Contrary to public and professional educational information released by the American Society of Anesthesiologists (ASA), a new study in the Journal of the American Medical Association (JAMA) suggests that patients may continue the use of some herbs until as few as 24 hours before surgery.1 In contrast, information from the ASA, which is based in Park Ridge, IL, recommends that herbs be discontinued at least two weeks before surgery.

The controversy has profound implications for the same-day surgery field. A recent study found that about one-third of patients in an ambulatory surgery setting admitted that they used herbal medications.2 And this statistic should really get your attention: More than 70% of the patients studied did not disclose their herb use during the routine pre-op assessment. In one case, a patient undergoing a laparoscopic cholecystectomy told his primary care physician and two surgical staff that he had not taken any medication.3 The patient subsequently experienced postoperative bleeding. Twenty-four hours later, the patient was questioned further and revealed that he took a multivitamin and two Ginkgo biloba tablets per day.

Chun-Su Yuan, MD, PhD, one of the authors of the JAMA study, says, "They’re thinking they’re not drugs,’ because they’re not physician prescription [medications]. Or patients think it’s not important, or they don’t want to be criticized by the physicians." Yuan is assistant professor in the department of anesthesia and critical care and a member of the Tang Center for Herbal Medicine Research at the University of Chicago.

Patients often think that physicians aren’t educated about herb use, according to one study.4 And the truth is, many physicians aren’t certain about what to do when the patients present them with herb information, complementary medicine experts say.

The JAMA article recommends that providers use a "targeted" approach when advising patients on discontinuing herbs before surgery. "The ASA recommendations for two or three weeks is very good, but sometimes not practical in our view," Yuan says. Many surgical patients have their preoperative visit conducted just a few days before surgery, he points out. "To say, Stop your herbs and come back in two weeks’ is not practical," Yuan says. "We got very specific [in our recommendations], based on our literature search."

Pharmacokinetic data indicate that some herbs are eliminated quickly and could be discontinued closer to the time of surgery, the study says. The study focused on the eight most common herbs: echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John’s wort, and valerian. These herbs account for 50% of all single-herb preparations sold, studies show.5-6 The authors made the following recommendations for discontinuation:

  • echinacea (purple coneflower root), no data;
  • ephedra (ma-huang), at least 24 hours before surgery;
  • garlic (ajo), at least seven days before surgery;
  • ginkgo (duck foot tree, maidenhair tree, silver apricot), at least 36 hours before surgery;
  • ginseng (American ginseng, Asian ginseng, Chinese ginseng, Korean ginseng), at least seven days before surgery;
  • kava (ava, intoxicating pepper), at least 24 hours before surgery;
  • St. John’s wort (amber, goatweed, hardhay, Hypericum, klamathe weed), at least five days before surgery;
  • valerian (all heal, garden heliotrope, vandal root), no data.

The concern about patients taking herbs before surgery is that some herbs, as well as dietary supplements, can affect the body’s ability to clot blood, surgery experts say. In addition, herbs can affect sedation, pain control, heart function, metabolism, immunity, and recovery, they say. (For more information on the impact of herbs, see Same-Day Surgery, April 2001, p. 43, and August 1999, p. 93.)

Study is criticized

The study has been criticized by some people with ties to the ASA because the recommendations aren’t based on double-blind, placebo- controlled studies.

"My opinion, basically, is that they didn’t do sound scientific studies to come up with discontinuation dates," says Jessie A. Leak, MD, associate professor in the Department of Anesthesia at the University of Texas, MD Anderson Cancer Center in Houston. Leak is one of the authors of the ASA publications, What You Should Know About Your Patients’ Use of Herbal Medicines and What You Should Know About Herbal Use and Anesthesia. (For an excerpt listing herbs, common uses, and side effects, see Same-Day Surgery, April 2001, insert. For ordering information on the pamphlets, see SDS, April 2001, resource box, p. 44.)

The JAMA authors examined how long it would take herbs to be excreted from the body and assumed that once the herbs were out of the body, it would be safe for the patient to have surgery, Leak says. "My opinion is that without well-designed patient safety studies, these are probably premature recommendations," she says. Leak says she is alarmed that practitioners might shorten the time to discontinue herbs before surgery without taking into account the effect of the herbs on various body systems. "Their margin of safety won’t be wide enough," she says.

Yuan acknowledges that the criticism of the basis of his study is valid, but adds, "This is the best we can do: Look at how long it takes the compound to be excreted from the system." The authors looked into the effects of the herbs, but most of the published studies have concentrated on pharmacological data, he says, "so our report was based on that."

What should you do?

With conflicting information coming from the ASA and the JAMA study, what should providers do? "Until we can get better patient safety studies, I’m going to stick with the two-week deadline," Leak says. "I’m very concerned, particularly with bleeding."

Experts offer these additional suggestions:

• Ask patients about herb use and document it.

Because most patients do not volunteer information on herb use when you ask them about medications, specifically ask them about herbs in the pre-op evaluation, experts suggest.2 "We recommend to nurses that they include in their pre-op assessment the use of herbal medicines by patients, and that they include that [use] in the interview questions," says Ramona Conner, RN, MSN, perioperative nursing specialist at the Association of periOperative Registered Nurses in Denver.

"If you ask, Are you taking any herbs or dietary supplement?’ you often get no,’" Yuan adds. "But if you list each herb, ask specific questions, we saw a high percentage taking herbs or dietary supplements."

However, simply asking about herbs isn’t sufficient, the JAMA authors maintain. One in five patients can’t identify which preparations they are taking.7 Therefore, ask patients to bring their herbs and other dietary supplements, as well as prescription medication, with them to the pre-op evaluation, experts suggest.

This step is important because the field of dietary supplements is unregulated, Leak says. "When we ask them to bring bottles, every bottle is the U.S. potentially could be different," she says. "[Also], it’s not at all uncommon for patients to be taking herbs that are mixtures." For example, ma-huang (Ephedra Sinica), which represents 17% of all dietary supplement use, is available in as many as 5,000 commercially available products, Leak says.

• Include your pediatric patients and their parents.

One study indicated that one in six parents reported giving dietary supplements to their children.8 "Echinacea is popular for use in kids," Leak warns. "Herb use has to be part of children’s [history and physical] too."

• Realize that even if patients discontinue herb use, they may suffer withdrawal.

Because withdrawal from conventional medications is associated with increased morbidity and mortality after surgery, withdrawal from herbs use may have a similar impact, the JAMA authors warn.9 "The danger of abstinence after long-term use may be similar with [alcohol and] herbal medications, such as valerian, which have the potential for producing acute withdrawal after long-term use," the authors say. They point to one case in which a patient who stopped taking valerian before surgery had delirium and cardiac complications postoperatively.10

Concerns over herb use before surgery are likely to grow. One publication estimates that 49% of the U.S. population has used an herbal product in the last year.11 Keep in mind that many of these patients will continue to take herbal medications up until the time of surgery. "Therefore, clinicians should be familiar with commonly used herbal medications to recognize and treat complications that may arise," the JAMA authors recommend. (For a list of web sites, see "Sources and resources," at the end of this article.)


1. Ang-Lee MK, Moss J, Yuan C. Herbal Medicines and Perioperative Care. JAMA 2001; 286:208.

2. Kaye AD, Clarke RC, Sabar R, et al. Herbal medications: Current trends in anesthesiology practice — a hospital survey. J Clin Anesth 2000; 12:468-471.

3. Fessenden JM, Wittenborn W, Clarke L. Ginkgo biloba: A case report of herbal medicine and bleeding postoperatively from laparoscopic cholecystectomy. Am Surg 2001; 33-35.

4. Blendon RJ, DesRoches CM, Benson JM, et al. American’s views on the use and regulation of dietary supplements. Arch Intern Med 2001; 161:805-810.

5. NBJ herbal and botanical U.S. consumer sales. Nutrition Business Journal 2000. Available at

6. Commission on Dietary Supplement Labels. Report of the Commission on Dietary Supplement Labels, Report to the President, Congress, and The Secretary of the Department of Health and Human Services. Washington, DC: U.S. Government Printing Office; 1997.

7. Kassler WJ, Blanc P, Greenblatt R. The use of medicinal herbs by human immunodeficiency virus-infected patients. Arch Intern Med 1991; 151:2,281-2,288.

8. Blendon RJ, DesRoches CM, Benson JM. Americans’ views on the use and regulation of dietary supplements. Arch Intern Med 2001; 161:805-810.

9. Kennedy JM, van Rij AM, Spears GF, et al. Polypharmacy in a general surgical unit and consequences of drug withdrawal. Br J Clin Pharmacol 2000; 49:353-362.

10. Garges HP, Varia I, Doraiswamy PM. Cardiac complications and delirium associated with valerian root withdrawal. JAMA 1998; 280-1,566-1,567.

11. Johnston BA. Prevention magazine assesses use of dietary supplements. HerbalGram 2000; 48:65.

Sources and resources

For more on discontinuing drugs before surgery, contact:

• Ramona Conner, RN, MSN, Perioperative Nursing Specialist, Association of periOperative Registered Nurses, 2170 S. Parker Road, Suite 300, Denver, CO 80231-5711. Telephone: (303) 755-6304, ext. 264. Fax: (303) 338-5165. E-mail:

• Jessie A. Leak, MD, Associate Professor, Department of Anesthesia, University of Texas, MD Anderson Cancer Center, 1515 Holcombe Blvd., Box 042, Houston, TX 77030. Telephone: (713) 792-6911. Fax: (713) 794-4590. E-mail:

• Chun-Su Yuan, MD, PhD, Assistant Professor, Department of Anesthesia and Critical Care, University of Chicago, 5841 S. Maryland Ave., MC 4028, Chicago, IL 60637.

For more information on herbs and other dietary supplements, see the following web sites: National Center for Complementary and Alternative Medicine, National Institutes of Health. Fact sheets about alternative therapies, consensus reports, and databases are included. Center for Food Safety and Applied Nutrition, Food and Drug Administration. Report adverse events associated with herbs and other dietary supplements. Safety, regulatory, and industry information are included. Agricultural Research Service, U.S. Department of Agriculture. A phytochemical database is included. ConsumerLab. This corporation performs independent laboratory investigations of dietary supplements and other products. HerbMed, a project of the Alternative Medicine Foundation. Information on more than 120 herbal medications is included. Significant research publications are summarized with Medline links. National Council Against Health Fraud. Includes a position paper on over-the-counter herbal therapies. Quackwatch. Includes significant amount of information on herbal and complementary therapies.