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Study finds herbs, surgery don't mix

By Rhonda Rowland
CNN Medical Unit

CHICAGO, Illinois (CNN) -- Physicians should ask all patients preparing to undergo surgery if they use herbal remedies, since they may cause complications during the operation, according to a study in this week's Journal of the American Medical Association. Doctors should also be familiar with the potential complications of commonly used herbal medications and know how to handle them, the researchers said.

"Surveys show about one-third of patients coming in for surgery will be taking herbs," said Dr. Jonathan Moss, an anesthesiologist at the University of Chicago who co-authored the study. "There is a reluctance among many of our patients to tell us about them ... because they consider them merely as nutritional substances without interfering biological activity."

He said doctors need to ask their patients about any herbal remedies they may be taking.

Moss and scientists at the Tang Center for Herbal Medicine Research at the University of Chicago examined the possible complications that could arise during surgery from eight common preparations, which account for about half of all herbal use.

Herbal medication effects and recommendations before surgery  

"We're all on alert here, because we're deeply suspicious that some of the issues that can occur in the perioperative period may be attributable to side effects of herbs" said Moss.

Researchers advise ginseng, St. John's wort and garlic supplements be discontinued a week before surgery, since they may increase bleeding and interact with other drugs. Ephedra, kava and ginkgo should be discontinued 24 to 36 hours before surgery because of possible cardiovascular effects and interference with anesthetic drugs. Echinacea may contribute to allergic reactions and valerian may increase sedative effects of anesthesia, though there aren't enough data to advise on when to discontinue use prior to surgery.

The recommendations are based on case reports and very limited scientific information. The authors found no controlled, randomized research on the effects of herbs on surgery. There are no incentives for scientific scrutiny since herbal remedies are only loosely regulated by the U.S. Food and Drug Administration.

"The literature attesting to this as scientific fact does not exist," said Norman Farnsworth, Ph.D., a research professor of pharmacognosy with the University of Illinois at Chicago College of Pharmacy.

"Because of the fact that there's no mechanism for adverse reporting for herbs as there is for drugs, one can't be absolutely certain," said Moss, "but we believe from our reading and study that there are enough case reports and information to indicate that one should be prudent."

The American Society for Anesthesiologists distributed an educational brochure last year about herbal remedies and surgery. The group is devoting an entire session to the potential complications at its upcoming scientific meeting.

"We want to do everything we can to prevent problems. And if problems develop despite that, we'll take care of it. But the knowledge going in is one of the most important weapons we have," said Dr. John Neeld, an anesthesiologist at Northside Hospital in Atlanta, Georgia, and past president of the American Society of Anesthesiologists.

Still, experts do not want patients awaiting surgery to be unduly alarmed.

"These are just reminders that these are biologically active. Even though the government considers them as dietary supplements by any scientific measure they're drugs," said Farnsworth. "If used according to the directions, these are probably the safest medicines that you could come across with a couple of exceptions."

For instance, Farnsworth says if a patient is taking prescription medications, St. John's wort should not be taken unless under a doctor's supervision.

Doctors say surgery and anesthesia are generally safe, especially in healthy people. But they add that informing your physician about your history of herbal remedy use can make the operating room even safer.



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