Unlike conventional over-the-counter or prescription drugs, which have required testing to document safety and effectiveness, dietary supplements are not held to these same strict standards. A report in a recent issue of Journal of the American Medical Association (JAMA, Vol. 286, Iss. 2: 208-216) reviews the literature on the use of herbal remedies as a factor contributing to complications during or after surgery.

In the JAMA report, Michael K. Ang-Lee, MD, and colleagues from the Pritzker School of Medicine, University of Chicago, conclude that some herbs can cause serious side effects for patients having surgery and they highlight the importance of good patient-physician communication in helping to prevent problems.

The report looks at the use of eight common herbs — echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John’s Wort, and Valerian — and provides information for doctors and their patients. Some of the problems patients can have include excessive bleeding due to garlic, gingko, and ginseng; heart problems from ephedra; and, low blood sugar from ginseng. Valerian and kava can add to the sedative effects of anesthetics. St. John’s Wort can influence metabolism of several drugs used before, during, and after surgery.

If doctors know their patients are using these herbs before surgery, they can adjust the doses of their conventional drugs to avoid complications. Even better, suggest Ang-Lee and colleagues, is for patients and their doctors to discuss this issue weeks before surgery. Based on this discussion, the doctor can predict which herbs are likely to cause problems and should be stopped, so that all effects of the herb is gone by the time of the operation.

Barrie Cassileth, MD, chief of integrative medicine service at Memorial Sloan-Kettering Cancer Center and member of the American Cancer Society advisory group on alternative and complimentary methods of cancer management, says, “Although the increasing popularity of dietary supplements has received considerable attention in medical journals and in the popular media, the issue is often not discussed by physicians and their patients.

“Patients may be reluctant to talk about over-the-counter remedies,” Cassileth says. “They may assume that these remedies do not ‘count,’ or are irrelevant, because they are natural products rather than prescription drugs. Concern about physician disapproval may play a role.”

“On the other hand,” Cassileth says, “physicians typically fail to ask about non-prescription therapies that patients are taking. They may not have the time to do so, and lack of knowledge about herbal remedies may make some reluctant to bring up a topic about which they can offer little in the way of informed advice.”

Cassileth concludes, “Herb use has important implications for radiation and chemotherapy as well as for surgery. Communication is a two-way street; physicians as well as patients have a responsibility to discuss patients’ self-prescribed remedies. Physicians should ask direct, open-ended questions to initiate communication and protect patients against disapproving reactions.”