title: Combination therapy of Western drugs and herbal medicines: recent advances in understanding interactions involving metabolism and efflux.
abstract: BACKGROUND
  While complementary and alternative medicine markets prosper with an increasing number of consumers of herbal medicines, there is an associated likelihood for herb-drug interactions to occur. Modulation of the activity of metabolic enzymes and/or active transporters by chemical constituents of herbal medicines may influence the therapeutic outcomes of coadministered allopathic medicines due to changes in their pharmacokinetic profiles. Although valuable information on herb-drug interactions is obtained by in vitro studies, such as the mechanisms of interaction, clinical significance of interactions is ultimately demonstrated by in vivo data.
  
  
  METHODS
  The authors outline the mechanisms of herb-drug pharmacokinetic interactions briefly and discuss pharmacokinetic interactions between different therapeutic classes of Western drugs and herbal medicines. Furthermore, the authors also discuss herb-drug interactions from both in vitro and in vivo studies with specific focus on recent findings.
  
  
  CONCLUSIONS
  Basic and clinical researches have contributed to the comprehension of the underlying mechanisms involved as well as the practical implications of herb-drug interactions. This provides a foundation for development of guidelines to inform patients about herb-drug interactions that can affect their health.
authors.affiliation: North-West University, Unit for Drug Research and Development, Private Bag X6001, Potchefstroom, 2520, South Africa.
authors.forename: Chrisna
authors.initials: C
authors.lastname: Gouws
authors.forename: Dewald
authors.initials: D
authors.lastname: Steyn
authors.forename: Lissinda
authors.initials: L
authors.lastname: Du Plessis
authors.forename: Jan
authors.initials: J
authors.lastname: Steenekamp
authors.forename: Josias H
authors.initials: JH
authors.lastname: Hamman
mesh_terms: D000871:Anthelmintics / Q000493:pharmacokinetics / Q000494:pharmacology; D044966:Anti-Retroviral Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D000935:Antifungal Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D000962:Antimalarials / Q000493:pharmacokinetics / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002317:Cardiovascular Agents / Q000493:pharmacokinetics / Q000494:pharmacology; D002490:Central Nervous System / Q000187:drug effects; D041743:Herb-Drug Interactions; D006728:Hormones / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D007155:Immunologic Factors / Q000493:pharmacokinetics / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000871:Anthelmintics; D044966:Anti-Retroviral Agents; D000935:Antifungal Agents; D000962:Antimalarials; D000970:Antineoplastic Agents; D002317:Cardiovascular Agents; D006728:Hormones; D007155:Immunologic Factors