Herb-drug interactions are
drug interactions that occur between
herbal medicines and conventional drugs. These types of interactions may be more common than drug-drug interactions because herbal medicines often contain multiple pharmacologically active ingredients, while conventional drugs typically contain only one. Some such interactions are
clinically significant, although most herbal remedies are not associated with drug interactions causing serious consequences. Most herb-drug interactions are moderate in severity. The most commonly implicated conventional drugs in herb-drug interactions are
warfarin,
insulin,
aspirin,
digoxin, and
ticlopidine, due to their narrow
therapeutic indices. The most commonly implicated herbs involved in such interactions are those containing
St. John’s Wort, magnesium, calcium, iron, or ginkgo.