Do any botanicals interfere with the metabolism of drugs?
To maintain the proper metabolism of certain drugs by cytochrome p450 (a liver enzyme), patients should discontinue use of the following agents. Increased metabolism of a drug reduces its concentration in the blood and may reduce its effectiveness. Decreased metabolism of a drug increases its concentration in the blood and can lead to toxicity or increased side effects. Essiac: A case of decreased clearance (removal from the blood) of an experimental chemotherapy is reported in a single patient taking Essiac. This may be due to inhibition of cytochrome p450 isoenzymes, hindering their ability to metabolize the chemotherapy agent. Garlic: May induce the cytochrome p450 3A4 isoenzyme, resulting in enhanced metabolism (and decreased effectiveness) of certain drugs. Ginkgo: Preliminary evidence suggests that ginkgo can affect the cytochrome enzymes 1A2, 2D6, and 3A4. However, data are controversial regarding whether ginkgo induces or inhibits individual enzymes. Ginseng (Siberian): Inhibit
