Interactions Between Conventional and Herbal Medicinal Products
Drug interactions are a commonplace occurrence, and with the majority of pharmaceuticals, such interactions are well characterized. These interactions may be beneficial, with augmentation of the effects of one of the agents used. However, interactions with adverse outcomes are also common. Harmful interactions can result in therapeutic failure of a drug or in a toxic outcome. Just as two drugs can interact, so can complementary products and drugs; such interactions are referred to as “herb-drug interactions” and, like all drug interactions, can be potentially harmful. Herb-drug interactions present their unique additional complications due to the complex and variable nature of the products and their somewhat random use.
Investigations into herb-drug interactions are challenging due to the very nature of the product; many components that may be active or inactive when isolated may behave very differently when in a mixture. Additionally, there is great product variability and currently, regulations requiring standardization or demonstration of product safety, are carried out mainly in developed parts of the world. Also, the methodology used to study herb-drug interactions can have a significant impact on the results obtained, and an understanding of these methods and the extrapolation of the data to human impact is required.
In this chapter we discuss herb-drug interactions of potential or reported clinical significance.
KeywordsHerb-drug interactions Investigation methods Pharmacokinetics Adverse event reporting
- Barnes P, Bloom B, Nahin R (2008) Complementary and alternative medicine use among adults and children: United States, 2007. National Health Statistics Report. U.S. Department of Health and Human ServicesGoogle Scholar
- Braun L, Cohen M (2010) Herbs & natural supplements − an evidence-based guide. Elsevier Australia (Sydney)Google Scholar
- Office of Inspector General (2001) Adverse event reporting for dietary supplements. An inadequate safety valve. Department of Health and Human Services - USA. Boston Regional Office, OEI-01-00-00180. Available at: http://www.dhhs.gov/oig/oei
- Guengerich FP (2005) Human cytochrome P450 enzymes. In: Ortiz De Montellano PR (ed) Cytochrome 450. Structure, mechanism and biochemistry, 3rd edn. Kluwer Academic/Plenum Publishers, New YorkGoogle Scholar
- Gurley BJ, Gardner SF, Hubbard MA, Williams DK, Gentry WB, Cui Y, Ang CY (2005a) Clinical assessment of effects of botanical supplementation on cytochrome P450 phenotypes in the elderly: St. John’s wort, garlic oil, Panax ginseng and Ginkgo biloba. Drugs Aging 22:525–539CrossRefPubMedPubMedCentralGoogle Scholar
- Gurley BJ, Barone GW, Williams DK, Carrier J, Breen P, Yates CR, Song PF, Hubbard MA, Tong Y, Cheboyina S (2006) Effect of milk thistle (Silybum marianum) and black cohosh (Cimicifugaq racemosa) supplementation on digoxin pharmacokinetics in humans. Drug Metab Dispos 34:69–74CrossRefPubMedGoogle Scholar
- Gurley BJ, Swain A, Hubbard MA, Williams DK, Barone GW, Hartsfield F, Tong Y, Carrier DJ, Cheboyina S, Battu SK (2008) Clinical assessment of CYP2D6-mediated herb-drug interactions in humans: effects of milk thistle, black cohosh, goldenseal, kava kava, St. John’s wort and echinacea. Mol Nutr Food Res 52:1–9Google Scholar
- Harkey MR, Henderson GL, Gershwin ME, Stern JS, Hackman RM (2001) Variability in commercial ginseng products: an analysis of 25. Clin Nutr 73:1101–1106Google Scholar
- Lefebvre T, Foster BC (2004) In vitro activity of commercial valerian root extracts against human cytochrome P450 3A4. J Pharmacol Pharm Sci 7:265–273Google Scholar
- Nelson DR (2009) The cytochrome P450 homepage. Hum Genomics 4(1):59–65Google Scholar
- Robinson MM, Zhang X (2011) Traditional medicines: global situation, issues and challenges. In: WHO/EMP/MIE (ed) The world medicines situation 2011. World Health Organization, GenevaGoogle Scholar
- Serbouce-Hougel S, Durand G, Corbii M, Agneray J, Feger J (1981) Alterations in relative proportions of microheterogenous forms of human alpha 1-acid glycoprotein in liver disease. J Hepatol 2:245–252Google Scholar
- Sevior DK (2012) Complementary products and drug interactions – screening for the potential to cause pharmacokinetic interactions. Doctor of Philosophy, RMIT UniversityGoogle Scholar
- Sevior D, Hokkanen J, Tolonen A, Abass K, Tursas L, Pelkonen O, Ahokas JT (2010) Rapid screening of commercially available herbal products for the inhibition of major human hepatic cytochrome P450 enzymes using the N-in-One cocktail. Xenobiotica 40:245–254Google Scholar
- Voulgari F, Cummins P, Gardecki T, Beeching N, Stone P, Stuart J (1982) Serum levels of acute phase and cardiac proteins after myocardial infarction, surgery, and infection. Br Heart J 1982:4Google Scholar
- World Health Organization (2008) Traditional medicine. WHO. http://www.who.int/mediacentre/factsheets/2003/fs134/en/