DALLAS--At a recent conference held by the American Society of Anesthesiologists (ASA), it was reported that certain herbs may cause complications during surgeries by interfering with anesthesia. Dr. Charles McLeskey of the Scott and White Memorial Hospital in Temple, Texas, reported that some of the most common herbal products, such as St. John's wort, garlic, kava kava and ginkgo biloba, could prolong the effects of anesthesia, cause fluctuations in blood pressure or increase bleeding during surgical procedures.

McLeskey advised physicians to ask patients if they are taking herbal supplements, prior to surgical procedures. The ASA recommended that all patients stop taking herbal supplements at least two weeks prior to surgery.