Supplements such as St. John’s wort, kava and ephedra could have dangerous interactions with anesthesia or other medications.

Most Americans don’t tell their doctors what herbal supplements they are taking. Prior to surgery, such an oversight could be disastrous.

If you’re undergoing a surgical procedure any time soon, you undoubtedly have a list of things you have to take care of first. At or near the top of that list should be one crucial reminder: stop taking herbal supplements and vitamins at least two to three weeks before the procedure.

More than a third of Americans take some kind of vitamin or herbal supplement–ginkgo biloba, garlic, ginseng, vitamin E–but 70 percent don’t tell their doctors. And even though these remedies may be “natural” and derived from food, many of them can be quite potent or even dangerous, particularly if misused.

Based on information that many popular supplements can interfere with anesthesia and with the body’s reaction to surgery, the American Society of Anesthesiologists issued a recommendation last year that patients should stop taking all natural remedies at least two weeks before any surgical procedure so the body will have plenty of time to clear these substances from the system.

More recently, an article in the Journal of the American Medical Association [July 11, 2001] outlined a number of potentially dangerous effects that could occur during surgery as a result of commonly used supplements such as echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John’s wort and valerian. The research team from the University of Chicago also reported actual instances of life-threatening effects such as bleeding or changes in blood pressure.

Clotting: Yes or No?
Many individuals take supplements such as vitamin E, ginkgo biloba and garlic to improve blood flow and prevent the blood clots that are so often associated with heart attacks.

That can be a good preventive practice, but it’s important to be aware of the cumulative effects of such substances. If your doctor has prescribed warfarin or asked you to take aspirin to prevent a heart attack, you shouldn’t start taking other anticoagulants without letting her know. Prior to surgery, such information is vital since any clotting abnormalities can lead to severe complications.

In a case cited by the University of Chicago research team, a patient who had been taking garlic supplements developed spinal bleeding and required a second operation to avoid permanent paralysis.

In another study, a 45-year-old woman scheduled for a hysterectomy mentioned at the last minute that she had been taking ginkgo for several weeks. After clotting studies were performed, her doctors decided to postpone the procedure rather than risk bleeding complications.

Other substances that have an effect on clotting include alfalfa, capsicum, celery, chamomile, Chinese herbs, fenugreek, feverfew, fish oil, ginger, ginseng, horseradish, kava, licorice, passionflower, red clover and vitamin E.

Many of these contain coumarins, natural agents that oppose blood clotting in a manner similar to warfarin (a synthetic coumarin).

BP: Up or Down?
Other supplements can affect blood pressure–either up or down. Black cohosh celery, fenugreek, garlic, hawthorn and horseradish tend to lower blood pressure while ephedra, goldenseal and licorice increase it. Ginseng, ginger and St. John’s wort may produce either an up or down effect.

While the usual goal is to lower blood pressure, either an up or down effect may be unwanted during a surgical procedure.

Most licorice candy in the United States is flavored with anise oil rather than licorice. However, pipe and cigar smokers and persons who chew tobacco may not realize that their tobacco is laced with enough licorice to have a dramatic effect on blood pressure, blood sugar and fluid retention.

Hawthorn is a herbal supplement some take for its beneficial effects on the cardiovascular system–dilating blood vessels and lowering blood pressure. Some doctors may even recommend hawthorn for patients with mild to moderate heart failure. During surgery, however, there is a risk that hawthorn could interact negatively with other heart medications–making their effect either more or less powerful than desired.

Perhaps because of its effect on stress hormones, ginseng, it is claimed, can calm you down if you’re hyper or give you energy if you’re sluggish. Yet there are many types of ginseng, and studies have revealed that an alarming number of products sold as ginseng are not ginseng at all but contain substances such as phenylbutazone, aminopyrine and mandrake root.

If you’re going into surgery, make sure you clear your system of all ginseng products. Risks include hypertension, clotting problems, hypoglycemia and rapid heart beat.

Unwanted Effects on Anesthesia
More than seven million Americans today take St. John’s wort, usually to relieve mild depression and anxiety. Believed by some to be the herbal Prozac, St. John’s wort has quickly become one of the most popular supplements, but several recent studies have revealed risks associated with its use–notably involving its effect on other medications.

If you’re taking HIV medications or anti-rejection drugs following an organ transplant, St. John’s wort can make them significantly less effective; if you’re taking birth control pills and St. John’s wort, you could become pregnant. In combination with anesthetics, on the other hand, St. John’s wort could create either an intensified or prolonged effect.

Kava, grown in the South Pacific Islands, is commonly taken to relieve nervous anxiety and stress. It also has a sedative action and an anesthetic activity similar to that of cocaine and is longer lasting than benzocaine. Doctors advise that you stop taking kava at least two weeks before surgery or dental procedures in order to avoid potentially severe effects including coma and Parkinsonian symptoms.

Ephedra, also known as ma huang, desert tea, natural ecstasy and natural “fen-phen,” is one of the most controversial of herbal supplements. Frequently taken for weight loss, it has been associated with a number of deaths.

Ephedra creates amphetamine-like symptoms, and side effects include heart attack, stroke and seizure. Surgical teams must be alert to any changes in the vital signs of a patient who has consumed ephedra products.

In making its recommendation to clear the system of all herbal supplements prior to surgery, the American Society of Anesthesiologists did not take a stand either for or against supplements.

Lacking regulation by the Food and Drug Administration, however, no herbal remedies can be taken with the assumption of either safety or efficacy. Some have established a good record; others may be downright dangerous.

Some medical schools today are including components on herbal and natural remedies in their curricula. But 70 percent of Americans don’t tell their doctors what herbal supplements and vitamins they are taking. Prior to surgery, such an oversight could be disastrous.

REFERENCES:
“Beware Supplements before Surgery,” Physician Assistant, February, 2001.
Cindy Brumley, “Herbs and the Periooperative Patient,” AORN Journal, November, 2000.
Paul Cerrato, “Herbs and Surgery Don’t Always Mix,” Contemporary OB/GYN, August, 2000.
W. Marvin Davis, “Dietary Supplements: Are They Safe and Reliable?” Drug Topics, April 16, 2001.
Tom Hollon, “NIH R.Ph.s Warn Consumers about Safety of Herbals,” Drug Topics, November 20, 2000.
Denise M. Jones and Philip S. Weintraub, “Anesthesiologists Warn: If You’re Taking Herbal Products, Tell Your Doctor before Surgery,” ASA Public Education, 1999.
Michael K. Ang-Lee, M.D., Jonathan Moss, M.D. Ph.D., Chun-Su Yan, M.D., Ph.D., “Herbal Medicines and Perioperative Care: Review,” JAMA, July 11, 2001.
Dorothy L. Pennachio, “Drug-Herb Interactions: How Vigilant Should You Be?” Patient Care, October 15, 2000.