Preoperative Evaluation: Herbals Away
Provided by: Chris Campton, RN, MS, GNP-C

Performing a thorough evaluation of patients before a surgical procedure is an important step in process to decrease the chance of a perioperative complication. Certain medications can have an impact on volume status, electrolyte balance, or coagulation. They may also interact with anesthesia. Most patients readily list medications they are taking or produce a card from their wallet with a list. Often however, unless prompted, they will not list those over-the-counter or herbal preparations that are not really considered "medicine".

Many herbals, if taken in large enough quantities, can have a very significant and unfavorable effect in the surgical setting. Although the mechanism of action is often not known, enough evidence exists to warn against using certain herbals prior to surgery.

The following is a partial list of herbals that patients should stop taking 7-10 days prior to surgery:

Herb Action:

  • Garlic Inhibits platelet aggregation
  • Dandelion Diuretic
  • Dong Quai Decreases blood pressure
  • Ephedra Increases blood pressure and pulse
  • Kava Decreases platelets, WBC's and albumin
  • Licorice Decreases potassium
  • Pau D'Arco Anticoagulation effect
  • St. John's Wort Possibly an MAO inhibitory effect. Stop 2-3 weeks prior to surgery.
  • Ginkgo Biloba Blocks platelet activating factor
  • Ginger Inhibits platelet aggregation
  • Feverfew Inhibits platelet aggregation


    Last updated:  June 10, 2000


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