Hepatotoxicity and complementary and alternative medicines.

Though some herbal medicines have been shown to protect against or treat experimental liver injury in vitro, and many may possess one or a combination of antioxidant, antifibrotic, immunomodulatory, or antiviral activities, they have not been shown effective in human trials. It has been extremely difficult to construct randomized, controlled trials using complementary and alternative medicines because of an incomplete understanding of their modes of action, the lack of standardization in their manufacture, and the complexity of ingredients in any herbal extract. This may become easier once more standardized and broad-based regulatory oversight of marketing and manufacture of these products is achieved. Despite this, the use of complementary and alternative medicines is ever increasing, especially in patients having chronic liver disease. With this growing popularity, it is becoming more apparent that many of these treatments possess the potential for appreciable hepatotoxicity, in some instances resulting in significant morbidity and mortality. Until these products are more closely regulated and their advertising better scrutinized, all physicians and patients should become more familiar with the natural and alternative products that are commonly used, and recognize which can be harmful (Table 4). Better public awareness should be maintained with regard herb and prescription drug interactions.