- 1Product
Safety & Regulatory Affairs, The Procter & Gamble Company,
Cincinnati, OH 45040, United States. Electronic address: roe.al@pg.com.
- 2Experimental
and Systems Pharmacology, College of Pharmacy, Washington State
University, Spokane, WA 99210, United States. Electronic address:
mary.paine@wsu.edu.
- 3College of Pharmacy, University
of Arkansas for Medical Sciences, Little Rock, AR 72205, United States.
Electronic address: GurleyBilyJ@uams.edu.
- 4Qualyst Transporter Solutions, Durham, NC 27713, United States. Electronic address: kennethbrouwer@qualyst.com.
- 5Marketed Biologicals, Biotechnology and Natural Health Products Bureau, Marketed Health Products Directorate, Health Canada, Ottawa, Ontario, Canada. Electronic address: ScottJordan@hc-sc.gc.ca.
- 6Council for Responsible Nutrition, Washington, DC 20036, United States. Electronic address: JGriffiths@crnusa.org.
Abstract
The use of natural products (NPs), including herbal
medicines and other dietary supplements, by North Americans continues
to increase across all age groups. This population has access to
conventional medications, with significant polypharmacy observed in
older adults. Thus, the safety of the interactions between
multi-ingredient NPs and drugs is a topic of paramount importance.
Considerations such as history of safe use, literature data from animal
toxicity and human clinical studies, and NP constituent characterization
would provide guidance on whether to assess NP-drug interactions
experimentally. The literature is replete with reports of various NP
extracts and constituents as potent inhibitors of drug metabolizing
enzymes, and transporters. However, without standard methods for NP
characterization or in vitro testing, extrapolating these reports to
clinically-relevant NP-drug interactions is difficult. This lack of a
clear definition of risk precludes clinicians and consumers from making
informed decisions about the safety of taking NPs with conventional
medications. A framework is needed that describes an integrated robust
approach for assessing NP-drug interactions; and, translation of the
data into formulation alterations, dose adjustment, labelling, and/or
post-marketing surveillance strategies. A session was held at the 41st
Annual Summer Meeting of the Toxicology Forum in Colorado Springs, CO,
to highlight the challenges and critical components that should be
included in a framework approach.
Copyright © 2016 Elsevier Inc. All rights reserved.
KEYWORDS:
Cytochrome P450; Dietary supplements; Drug interactions; Herbal medicines; Metabolic enzymes; Natural products; Transporters
