Herbal medicines and interactions with anesthetic agents.

Herbal medicines have enormous presence world wide. Herbs are listed under the "supplement" category by the food and Drug Administration in the USA. The Dietary Supplement and Health Education Act signed into law in October 1994, requires no proof of efficacy, no demonstration of safety, and sets no standards for quality control for the products labeled as "supplements" thereby increasing the risk of adverse effects as quantities of active agents are unregulated. The United States has experienced an epidemic of over-the-counter "natural" products over the last two decades; but there is little motivation for the manufacturers to conduct randomized, placebo-controlled, double-blinded clinical trials to unequivocally prove the safety and efficacy of these drugs. Physicians must enquire and be aware of herbal/drug interactions. In addition, patient education of the potential interactions should be a routine component of preoperative assessment. The American Society of Anesthesiologists (ASA) recommends that all herbal medications should be discontinued 2-3 weeks prior to an elective surgical procedure. If the patient is not sure of the contents of the herbal medicine, he/she should be urged to bring the container so that an attempt can be made to review the contents of the preparation. While such an action holds some promise in the elective setting, emergency care should be based on a thorough drug-intake history from the patient or a relative, if possible. Medical research and medical literature in general has not addressed this new group of health supplements, despite the fact that many of these herbs have the potential to cause serious health problems and drug interactions. There is a need to conduct scientific clinical trials to study the anesthetic drug responses to commonly used neutraceutical agents.