title: Pharmacokinetic herb-drug interactions: are preventive screenings necessary and appropriate?
abstract: Pharmacokinetic interactions often occur as a result of activity changes of drug-metabolizing and transporting proteins, especially cytochrome P450 (CYP) isoenzymes and P-glycoprotein (P-gp). The activity of these enzymes and drug transporters can be enhanced or inhibited by synthetic drugs as well as by natural products. Since the number of herb-drug interactions has increased in recent years, systematic in vitro screenings and more clinical studies to identify such interactions were proposed for herbal medicinal products. However, previous results regarding this issue are not only contradictory but also of less predictability. One reason for the discrepancies could be the lack of validation of the recommended in vitro tests. Furthermore, it has to be considered that pharmacokinetic drug interactions are not only mediated by herbal medicines but also by several foods, beverages and life-style products. Since herbal medicines are considered to have a broad therapeutic range, a preventive risk assessment for pharmacokinetic drug interactions should first be realized for synthetic drugs with a narrow therapeutic index. Efforts to identify all possible interactions will lead to limitless investigations and to inconsistent decisions.
authors.affiliation: Department of Pharmaceutics, University of Florida, Gainesville, FL, USA.
authors.forename: Veronika
authors.initials: V
authors.lastname: Butterweck
authors.forename: Hartmut
authors.initials: H
authors.lastname: Derendorf
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Gaus
authors.forename: Adolf
authors.initials: A
authors.lastname: Nahrstedt
authors.forename: Volker
authors.initials: V
authors.lastname: Schulz
authors.forename: Matthias
authors.initials: M
authors.lastname: Unger
mesh_terms: D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D018565:Food-Drug Interactions; D041743:Herb-Drug Interactions; D006801:Humans; D008517:Phytotherapy; D010936:Plant Extracts / Q000378:metabolism* / Q000493:pharmacokinetics; D010946:Plants, Medicinal
chemical_list: D010936:Plant Extracts; D003577:Cytochrome P-450 Enzyme System