Herbal medicines may interact with the medicines used during anesthesia or cause other problems during the surgical procedure or your recovery. Some of the bad side effects when taking herbals prior to surgery include increased bleeding, heart and blood pressure changes, longer sedation than desired, and changes in the way other medicines react in the body. To be safe, people who know they are going to have surgery should stop taking all herbal medicines 1 to 2 weeks before the procedure, according to the American Society of Anesthesiologists. This general timeframe errs on the side of caution, as the effects of many herbals are short-lived after stopping their use. Be sure to let your surgeon and anesthesiologist know if you have been taking an herbal medicine and when (or if) you stopped taking it before surgery.
Black cohosh: This herbal may interact with anesthesia medicines and cause a low blood pressure or increased risk of bleeding.
Echinacea: Because echinacea is believed to boost the immune system, transplant patients should avoid this herbal both before and after surgery. Long-term use of echinacea can also result in liver damage, which may increase the effects of some medicines used during anesthesia.
Ephedra (herbal ecstasy): Ephedra can cause serious heart and blood pressure effects. In combination with anesthesia medicines, its can cause life-threatening or fatal heart irregularities, elevated blood pressure, and a dangerous rise in body temperature.
Feverfew: Combined with anesthesia medicines, this herbal may cause prolonged bleeding during and after surgery and migraine headaches, anxiety, and insomnia after surgery.
Garlic: This common cooking ingredient can increase the blood pressure and the risk of bleeding during and after surgery. It should be stopped a full week (7 days) prior to surgery.
Ginger: Although this herbal medicine stimulates the gastrointestinal tract, there is no increased risk for nausea and vomiting after surgery. However, ginger increases the amount of time it takes for blood to clot, so it should be stopped before surgery, especially by those who also take certain pain relievers such as ibuprofen, ginkgo biloba, or warfarin (blood thinner).
Gingko biloba: Bleeding is possible during and after surgery when taking this herbal. Numerous instances of bleeding in the brain have been reported.
Ginseng: During surgery, ginseng may increase the risk of bleeding, dangerously lower the blood sugar, and increase the risk of bad side effects involving the heart. The herbal medicine should be stopped at least 7 days before surgery.
Hoodia: This herbal medicine causes changes in the blood sugar and increases the risk of bad side effects involving the heart.
Kava: This herbal can increase the effects of certain anesthesia medicines, causing more sedation than required. It can also increase the effects of sedation and increase the risk of liver injury.
St. John’s wort: This herbal can significantly increase the effects of anesthesia medicines, causing prolonged sedation. St. John’s wort also reduces the effectiveness of warfarin, which is used to prevent blood clots. This herbal should be stopped at least 5 days prior to surgery. It is particularly important to stop taking St. John’s wort if awaiting a transplant or undergoing a surgical procedure that may require medicine to prevent blood clots before and/or after surgery.
Valerian: Longer sedation from anesthesia medicines may occur when taking valerian. Suddenly stopping this herbal may result in withdrawal symptoms, including abdominal pain, aching joints, anxiety, hostility, confusion, and many other serious symptoms. Thus, valerian should be stopped over the course of a 1-2 weeks, decreasing the dose gradually.
1. Wong A. Townley SA. Herbal medicines and anaesthesia. Contin Educ Anaesth Crit Care Pain. 2011;11(1):14-7.
2. American Society of Anesthesiology. What you should know about herbal and dietary supplement use and anesthesia. 2003. Patient Information Leaflet.