New Recommendations for Herbal Use Discontinuation
By Aman Shah, MD
WebMD Medical News
Reviewed by Michael W. Smith, MD
July 10, 2001 -- There have been numerous reports about how patients are not disclosing their herbal supplement use to physicians for any number of reasons, but a review in the July 11 issue of JAMA shows that this could be a particularly dangerous practice when brought into the operating room. Researchers pinpoint potential problems with herbs in the perioperative period and offer guidelines on when various herbs should be discontinued prior to surgery.
"The American Society of Anesthesiologists' position was that everyone should stop [herbal medications] 2 weeks before surgery," says co-author Jonathan Moss, MD, PhD. "Practically, that's very difficult because many of our patients we don't even know about until a few days before surgery. [We] were trying in this paper to provide physicians with a better sense -- a framework -- for what they should do and what they should tell patients."
In their report, senior researcher Chun Su Yuan, MD, and colleagues reviewed data on 8 of the most common herbal medications: echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John's wort, and valerian -- which account for about half of all herbal use in the U.S.
Based on their review of studies, case reports, and other reviews on these supplements, the researchers say taking any of these medications just prior to surgery can affect heart rate, increase the risk of bleeding, alter immune function, and even interfere with anesthesia and pain management.
Because the effects of some herbal medications can last 2-3 weeks after discontinuation, Yuan and colleagues have come up with specific recommendations for when patients should discontinue certain herbal medicines if they are scheduled for surgery.
The recommendations advise discontinuing the following:
Ephedra and kava -- at least 24 hours before surgery
Ginkgo -- at least 36 hours before surgery
St. John's wort -- at least 5 days before surgery
Garlic and ginseng -- at least 7 days before surgery
Echinacea -- as far in advance as possible
Valerian -- taper dose several weeks before surgery if possible or continue to use until surgery under supervision
The researchers note the following potential adverse effects for these drugs:
Ephedra -- There are more than 1,000 reported adverse effects including fatal cardiac and CNS complications, largely due to dose-dependent increases in heart rate, vasoconstriction that may lead to thromboembolic phenomena, arrhythmias, and myocarditis. It can be fatal if used with MAO inhibitors.
Kava -- This sedative and anxiolytic may potentiate anesthesia and rarely may even lead to coma. Heavy use may lead to dermatologic effects.
Ginkgo -- Ginkgo may alter vasoregulation, interfere with neurotransmitter function, and alter platelet function, leading to increased postoperative and internal bleeding complications.
St. John's wort -- This herb may significantly increase the metabolism of several drugs that are metabolized in the P450 cytochrome system, including warfarin, NSAIDs, indinavir, estradiol, cyclosporine, and many others. It may also interfere with digoxin pharmacokinetics.
Garlic -- Garlic inhibits platelet aggregation and may potentiate the effects of other drugs that alter platelet function, leading to bleeding complications. It also mildly reduces blood pressure.
Ginseng -- Appears to have steroid-type effects in reducing stress responses. It may cause hypoglycemia, alter platelet function, and increase coagulation times.
Echinacea -- Appears to stimulate immune function and may interfere with immunosuppression. It can induce allergic reactions and anaphylaxis and may be hepatotoxic.
Valerian -- This sedative and hypnotic may interfere with anesthetic agents. The researchers note that it can cause a benzodiazepine-like withdrawal syndrome and should be tapered instead of abruptly discontinued, if possible.
Yuan, associate director of the Tang Center for Herbal Medicine Research at the University of Chicago, says about 22% of people scheduled for surgery report using some form of herbal medication. But according to Moss, that number may be even higher because many patients don't report use even when specifically asked.
"Even when you do get an answer, you don't know how much is in what they're taking because even if you know the total content there are big differences ... in the biological components," says Moss, professor of anesthesia at the University of Chicago.
Moss says the number of patients who have had problems after surgery as a result of taking herbal medications is reported to be in the hundreds, but that figure may be the "tip of the iceberg" because there is no real reporting system.
"It's definitely a problem," says Mary Ann Richardson, DrPH, researcher at the National Institutes of Health's National Center for Complementary/Alternative Medicine. "One of the main reasons patients don't talk about these things is because physicians never ask them. Or they think they may get some sort of negative response ... or they think the physician won't know anything about it, which is generally true."
She says the topic needs to be brought up more often, and doctors need to let patients know it's OK to talk about it.
Moss says the American Society of Anesthesiologists is devoting a forum to this topic at their annual meeting this year because of a sense that the problem is growing larger and no one knows how to deal with it.