As the use of herbal supplements becomes more widespread, it is vitally important that the anesthetist has a detailed understanding of potential interactions with anesthetic medications and full knowledge of the perturbations these herbal remedies can have on patient physiology in a perioperative setting. The first question to ask after reviewing conventional medications is: “Do you take any herbal supplements/medications that are not documented in your chart? It may have an impact on your surgery and/or anesthetic.” The caveat is that patients do not always know to report supplements as medications. They may not understand the scope of properties these supplements have when not discontinued before surgery, especially when they will be exposed to a number of different medications during the perioperative and postsurgical course. A common recommendation is to refrain from taking herbal remedies for at least 2 weeks prior to surgery. This recommendation is not standard or widespread, and it is impossible to enforce due to noncompliance or emergency surgical situations. A pertinent, concise description is valuable to enhance understanding of these herbal remedies and avoid catastrophic outcomes due to inadequate consideration of these drugs effects. What follows is a review of few of the more commonly prescribed supplements that influence anesthetic drug action. A summary of these herbal remedies is presented in Table 13–1.
| Herbal Remedy | Clinical Effects | Mechanism of Action | Anesthetic Implications |
|---|---|---|---|
Garlic (Allium sativum) Source: Bulb from onion-like garlic plant | Known effects: Decreased blood pressure Decreased cholesterol Decreased lipids Decreased thrombus formation | Dose-dependent platelet aggregation inhibition | Increased risk of bleeding Possible potentiation of other platelet aggregation inhibitors |
Echinacea (Echinacea purpurea) Source: Coneflower, a flower from the daisy plant family | Purported effects: Immune system stimulant Prophylaxis/treatment of viral, bacterial and fungal infections, particularly upper respiratory infections Antidepressant | Unknown, may increase l-dopa levels | Consider avoiding in patients who require immunosuppression CYP3A4 inhibitora Consider avoiding when coadministered with other potential hepatotoxic drugs |
Valerian (Valeriana officinalis) Source: Valerian root | Purported effects: Sedation Anxiolysis Sleep aid | Potentiates GABA-ergic system | May potentiate benzodiazepines, opioids, and sedative hypnotics May cause withdrawal postoperatively with abrupt cessation |
Ephedra (ma huang) Source: Ephedra plant | Known effects: Stimulant | α-1-, β-1-, and β-2-receptor agonism | Fatal cardiovascular events (myocardial infarct, stroke, death) Perioperative hemodynamic instability Catecholamine depletion Adverse cardiovascular effects when mixed with MAOIs |
Ginkgo (Ginkgo biloba) Source: Leaf of ginkgo plant | Known effects: Improved cognitive function Antioxidant Inhibitor of platelet activation Altered vascular tone | Partially understood; flavonoids, terpenoids, and organic acids protect from oxidative damage. | Rare postoperative bleeding |
St. John’s wort: (Hypericum perforatum) Source: Shrub plant of the same name containing hypericin and hyperforin | Purported effects: Antidepressant | Inhibition of serotonin, norepinephrine and dopamine reuptake | Induction of hepatic cytochromes CYP3A4 and CYP2C9; this may decrease effect from: Warfarin Alfentanil Midazolam Lidocaine Calcium channel blockers Serotonin antagonists NSAIDS |
Ginseng: (Panax ginseng) Source: Perennial plant of the same name containing ginsenosides a steroidal saponins | Purported effects: Protection from stress and restore homeostasis Decrease glucose levels Anticoagulation | Poorly understood, but considered similar to steroid hormones | Hypoglycemia in fasting patients Perioperative bleeding |
Kava (Piper methysticum) Source: Roots of the Kava plant | Purported effects: Sedative Anxiolytic | May influence GABA-ergic system | May potentiate sedative–hypnotics |
Ginger: (Zingiber officinale) Source: Rhizome (roots) of ginger plant | Purported effects: Anti-Inflammatory Antiemetic | Potent inhibitor of thromboxane synthetase | Potential for increased risk of prolonged bleeding, especially when coadministered with NSAIDs and/or warfarin |
Garlic is a popular herbal supplement that is thought to aid in control of atherosclerotic disease. It is available in many different pill and capsule formulations. Its use in prevention of atherosclerotic disease is based on findings published in 1986 that it decreases thrombosis by dose-dependent inhibition of platelet aggregation inhibition, reduces blood pressure, and lowers cholesterol.1
Allicin and alliin (organosulfur-containing compounds) are thought to be responsible for garlic’s mechanism of action. Animal studies have demonstrated a reduction of atherosclerosis, intra-arterial fat deposition, normalized lipoprotein balance, and inhibition of platelet aggregation.2,3, and 4 Ajoene, another constituent, may cause irreversible platelet inhibition. Human studies have yielded the same results with regard to lowering cholesterol.5,6
Since garlic may potentiate effects of other anticoagulants and antiplatelet and anti-inflammatory drugs, clinicians may consider having patients stop garlic consumption 7 to 14 days prior to surgery, especially with surgical procedures associated with significant blood loss or worrisome complications from persistent unanticipated anticoagulation.
