Preanesthetic evaluation. Importance of herbal drug usage in anesthesia practice.

P are used widely in many countries as folk remedies, nutritional support and herbal drugs. People believe that these natural products are safe and harmless. Exaggerated news regarding herbal products is available nearly everyday in audiovisual and printed media. Combinations of herbal medicines with conventional prescribed medicines may be dangerous. Especially in the context of anesthesia, where multiple drugs are administered over a short period, herbal products represent a potential risk to patient safety. This is particularly the case if the anesthetist is not aware that the patient is taking such a product. During preanesthetic evaluation, routine drug usage is questioned but herbal products are not.1-5 We started a study to question the extent of herbal medicine use in patients undergoing/receiving surgery and anesthesia, and to determine the most frequently used herbals. The study was started after the approval by the Clinical Research Ethics Committee of Dokuz Eylul University Medical School. A questionnaire consisting of 10 questions was given to 997 patients during a 12 months period. We included all patients above 18 years undergoing elective surgery. On completion of each preanesthetic evaluation, patients were administered the questionnaire to determine their usage of any drug and any herbal medicines and related dietary supplements, including multivitamins. As part of each preanesthetic evaluation, patients were asked if they were taking any medications or drugs. The questionnaire included a list of commonly used herbal medicines listed by their generic names. A space was allowed for patients to include any product that was not on the list. The questionnaire included questions regarding the demographic features (gender, age, education) concomitant drug, vitamin, and herbal use, application methods, reasons for beginning that therapy, whether the patient was questioned or not for herbal drug usage during previous anesthesia and whether he/she has information regarding the side effects of herbal products or not. The survey population included 57.7% female, 42.2% male patients, and the range of age was between 18-89 years (47.5 ± 16). Answers to the education level were 0.2% no answer, 9.2% primary school, 12.1% secondary school, 42.9% high school, 20% university, 15.6% postgraduate. It was reported that 22-43% of the patients undergoing surgery, used herbal products.1 Kaye et al1 questioned 1017 patients, preoperatively regarding herbal use. Thirty-two percent responded with yes, and 43% of the patients used garlic extracts, 32% Gingko biloba, 30% St. John’s wort, 18% Ma Hung, 12% Echinacea, 10% Aloe, 8% Cascare, and 3% licorice. Vaabengaard and Clausen2 reported that patients use fish oil, gingko, Echinacea, Ca-Q10, and garlic very frequently. Various surveys have shown general usage to range from 16-17% up to 60-70% of U.S. adults using herbs in the past year. Vitamin C was reported to be the most frequently used dietary supplement.3 In our study, herbal product use was 50.9% in adults, and 20% of the subjects were using more than one product. In our study herbal product usage was high, as in the Aegean Region people eat dominantly vegetables; they have a high education level and so are ambitious to try new treatments they read in newspaper, book or internet. In addition to herbal products, 24.7% of our patients were using multivitamin complexes (B1, B6, B12, Vit A, and Vit C). Sixteen percent of the patients were using garlic. Garlic decreases blood pressure and cholesterol levels and inhibits platelet aggregation.3-5 Gingko improves cognitive functions and peripheral perfusion (impotence, macular degeneration) and inhibits platelet activation. St. John’s wort improves slight and moderate depression. The major problem with this herbal is its potential to change the other drugs’ metabolism. It increases the drug’s metabolism with cytochromeP450.3,5 Ephedra is used to support weight-loss and to increase the energy consumption. It leads to sympathetic stimulation such as ephedrine with increased heart-rate and blood pressure, dysrhythmias, myocardial infarction and stroke, so monoamine oxidase inhibitors must be avoided. Ephedra interacts with volatile anesthetics (halothane, desflurane, isoflurane). Gingko biloba, kava kava, and Echinacea can elongate the duration of sedation and effective period of barbiturates.1,3 Ephedra and ginseng can cause hypertension with long-term usage.3 Licorice has a widespread use for intestinal problems and its side effects are high bloodpressure, arrhythmias, sodium retention. It can cause cardiac problems due to significant hypokalemia. Electrocardiography changes can be seen during anesthesia due to electrolyte changes. Metabolic activity of cytochrome P450 3A4, can change the metabolism of many drugs. It also inhibits platelet aggregation.5 Echinacea stimulates the immune system. It shows allergic reactions, hepatotoxicity Preanesthetic evaluation