Interactions

Interactions with Drugs

Animal studies suggest that milk thistle may interfere with the way the body processes certain drugs using the liver's "cytochrome P450" enzyme system. As a result, the levels of these drugs may be increased in the blood, and may cause increased effects or adverse reactions. Many types of drugs may be affected. Individuals should speak with a qualified healthcare provider to obtain a list of these drugs and their possible interactions. In theory, milk thistle may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.

A possible interaction with phenytoin (Dilantin®) has been reported with milk thistle. However, the facts are unclear.

Milk thistle ingredients have been reported to prevent amiodarone toxicity in animal studies. Based on laboratory and animal study, milk thistle may increase the effects of chemotherapy drugs like doxorubicin, cisplatin, and carboplatin. Milk thistle may interact with hormonal agents, alcohol, antiretroviral drugs, or indinivir.

Interactions with Herbs and Dietary Supplements

Animal studies suggest that milk thistle may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements may be too high in the blood. It may also alter the effects that other herbs or supplements have on the P450 system.

Milk thistle may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

Milk thistle may also interact with herbs and supplements with hormonal, antiretroviral or antioxidant effects. Milk thistle may chelate iron and slow calcium metabolism.