Herbal Remedies in the United States: Potential Adverse Interactions With Anticancer Agents

Abstract

It is suggested that health care professionals and consumers should be aware of the potential for adverse interactions with these herbs, question their patients on their use of them, especially among patients whose disease is not responding to treatments as expected, and urge patients to avoid herbs that could confound their cancer care.

Pungent ginger components modulates human cytochrome P450 enzymes in vitro

“…There is an increasing interest in determining the importance of drug-drug, drug-nutrient, and drug-dietary supple- [18][19][20] . It is necessary to evaluate the potential influence of gingerols on human drug metabolism.…”

Dietary Supplement Use in Cancer Care: Help or Harm

“…Herb-drug interactions, the form of adverse effect most often mentioned by oncologists, has been the subject of a number of reviews [38][39][40][41][42]. Despite these reviews and the concerns they raise, only two articles were identified that specifically tried to assess the degree of risk encountered by use of dietary supplements, including herbs, during cancer care [41,43].…”

“…Potential for interaction has also been raised with adenosine triphosphate binding-cassette transporters, such as P-glycoprotein, multidrug resistance associated protein-1, and breast cancer resistance protein [38]. Although herbal remedies have been shown to both up-and down-regulate the activity of a variety of P450 isozymes in screening tests, relatively few human clinical trials exist to validate these results [44].…”

“…Although herbal remedies have been shown to both up-and down-regulate the activity of a variety of P450 isozymes in screening tests, relatively few human clinical trials exist to validate these results [44]. One review by Sparreboom and colleagues [38] attempted to assess the likelihood of interaction of a number of common herbal agents with chemotherapy based on a wide variety of preclinical, animal, and human data. The investigators concluded that interactions with saw palmetto (Serenoa repens), cranberry (Vaccinium macrocarpon), black cohosh, milk thistle (Silybum marianum), and bilberry (Vaccinium myrtillus) were not expected, while specific cautions were made for garlic, ginkgo (Ginkgo biloba), soy (Glycine max), ginseng (Panax ginseng), valerian (Valeriana officinalis), and kava, largely on the basis of preclinical data.…”

Pharmacokinetics and Drug Interactions of Herbal Medicines: A Missing Critical Step in the Phytomedicine/Drug Development Process

“…The use of complimentary alternative medicine alongside conventional therapy continues to grow rapidly especially in the developed countries. It is estimated that less than a third of Americans taking botanical products inform their physicians of such use (7). In oncology therapy alone, about 72% of cancer patients taking herbal medicines with their conventional treatments do not inform their physicians (8) and 27% of them were at risk for developing herb -drug interaction (9).…”