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F. J. BRINKER, Program in Integrative Medicine, Univ. of Arizona Health Sciences Center, 1501 N. Campbell Ave., PO Box 245018, Tucson, AZ 85724-5018 As new information appears regarding the potential influence of food, drink, and/or dietary supplements on drug effects, the possibility of problems increases. Uncertain risks for patients and consumers, and challenges for suppliers, educators, and practitioners to accurately interpret the findings of research and cases reports. Serious difficulties arise from extrapolating laboratory data, whether animal research or cellular mechanistic studies. Likewise, studies on isolated compounds do not necessarily represent outcomes when these components are consumed as part of a natural complex matrix. This review addresses commonly utilized complex forms of natural products and utilizes human studies and cases to document their actual, rather than potential, interactions with drugs as the most appropriate means of assessing interactions with relative certainty. Interactions affecting drug kinetics are the least obvious and most challenging. Some influences on absorption are documented and predictable on the basis of common physical and chemical properties of natural substances. Other effects on cellular transport proteins and metabolic isozymes can only be determined through discriminating research, as is also true of influences on post-absorption drug bioavailability. Variations of the interacting product's form, content, dose, dose schedule, and duration can determine the relative outcome, making accurate characterization of the studied products and protocols essential. The value of the research depends on these explicit descriptions. Pharmacodynamic interactions are more predictable, such as additive or adjunctive combined effects. Some combinations of drugs with active botanicals have been found to result in adverse effects, while others have enhanced therapeutic outcomes, reduced drug dosage, and/or diminished drug adverse effects. The evidence for beneficial outcomes is reason to further examine possibilities of integrating, rather than simply avoiding, interactions between natural products and pharmaceuticals.
Session 104, Food-drug interactions: A new challenge for phytochemical research and industry
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |