Herbal interactions with cardiovascular drugs.

The prevalence of herb-drug interactions has been exaggerated. Nonetheless, some herbs, including garlic, ginkgo, ginseng, and St John's wort, can have a significant influence on concurrently administered drugs. Herbal medicines may mimic, decrease, or increase the action of prescribed drugs. This can be especially important for drugs with narrow therapeutic windows and in sensitive patient populations such as older adults, the chronically ill, and those with compromised immune systems.