Dietary Supplements in Patients With Cancer: Risks and Key Concepts, Part 2

Laura Boehnke Michaud, Julie Phillips Karpinski, Kellie L. Jones and Janet Espirito


Am J Health Syst Pharm. 2007;64(5):467-480. 

In This Article

Supplements with Known or Theoretical Drug Interactions

Many reviews have been published about drug–nutrient and drug–supplement interactions.[186,187,188,189] It has become apparent that effects on absorption, metabolism, and excretion are not restricted to prescription drugs. Research has revealed substantial interactions between many prescription medications and the consumption of grape-fruit juice.[190] The effects of St. John’s wort on CYP isoenzymes have also been well-defined through diligent observations and detailed research.[191] These interactions are typically reported involving a prescription medication, but supplement–supplement interactions are also possible and much more difficult to identify. Caution should be taken whenever more than one medication or supplement is added or dietary intake significantly altered. Information regarding these types of effects may be found in many databases and the primary literature.


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