Herbs: Toxicities and Drug Interactions

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Any conventional medication can have side effects. These side effects are described and reported after drug trials and research studies have been conducted. Side effects are further reported and evaluated after the marketing of the medication. Information about drug components, interactions, usage in pregnancy, while breastfeeding, for pediatric patients, and dosing limits are outlined and made available in standard references for doctors treating patients. Furthermore, the formulations of the drugs must satisfy strict quality control standards to ensure conformity. These medications regularly contain virtually uniform quantities and ratios of substances.

In contrast to conventional medications, unconventional treatments (such as herbs) have little or no actual scientific basis so doctors can guide their patients regarding proper usage or potential toxicity. There are no standardized references and most of the herbal formulations have not been analyzed, are not uniform, and have not been quality controlled. One batch can be very different from the next.

Moreover, even if a given herb has a known toxicity, the manufacturer may or may not warn consumers. Manufacturers are not required to alert consumers to known dangers.

The point is that these "supplements" are not sanctioned, regulated, or supervised by any agency.

Data is coming, although slowly. Dr. Lucinda Miller of Texas Tech University Health Sciences reviewed known herb-drug interactions. Her review was published for doctors in the medical journal Archives of Internal Medicine. The list that follows is derived from this article and includes summaries of various herbs with particular focus on potential herb-drug interactions.