| Medications as a Potential Source of Exposure to Phthalates in the U.S. Population Sonia Hernández-Díaz,1 Allen A. Mitchell,2 Katherine E. Kelley,2 Antonia M. Calafat,3 and Russ Hauser1,4 1Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, USA; 2Slone Epidemiology Center at Boston University, Boston, Massachusetts, USA; 3National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA; 4Department of Environmental Health, Occupational and Environmental Medicine and Epidemiology Program, Harvard School of Public Health, Boston, Massachusetts, USA Abstract
Background: Widespread human exposure to phthalates, some of which are developmental and reproductive toxicants in experimental animals, raises concerns about potential human health risks. Underappreciated sources of exposure include phthalates in the polymers coating some oral medications. Objective: The objective of this study was to evaluate whether users of phthalate-containing medications have higher urinary concentrations of phthalate metabolites than do nonusers. Methods: We used publically available files from the National Health and Nutrition Examination Survey for the years 1999–2004. For certain survey periods, participants were asked to recall use of prescription medication during the past 30 days, and for a subsample of individuals, the urinary concentrations of phthalate metabolites were measured. We a priori identified medications potentially containing phthalates as inactive ingredients and then compared the mean urinary concentration of phthalate metabolites between users and nonusers of those medications. Results: Of the 7,999 persons with information on urinary phthalate concentrations, 6 reported using mesalamine formulations, some of which may include dibutyl phthalate (DBP) ; the mean urinary concentration of monobutyl phthalate, the main DBP metabolite, among these mesalamine users was 50 times higher than the mean for nonusers (2,257 µg/L vs. 46 µg/L ; p < 0.0001) . Users of didanosine, omeprazole, and theophylline products, some of which may contain diethyl phthalate (DEP) , had mean urinary concentrations of monoethyl phthalate, the main DEP metabolite, significantly higher than the mean for nonusers. Conclusion: Select medications might be a source of high exposure to some phthalates, one of which, DBP, shows adverse developmental and reproductive effects in laboratory animals. These results raise concern about potential human health risks, specifically among vulnerable segments of the general population and particularly pregnant women and children. Key words: coating, didanosine, medications, mesalamine, omeprazole, phthalates, theophylline. Environ Health Perspect 117:185–189 (2009) . doi:10.1289/ehp.11766 available via http://dx.doi.org/ [Online 7 October 2008]
Address correspondence to S. Hernández-Díaz, Pharmacoepidemiology Program, Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115 USA. Telephone: (617) 432-3942. Fax: (617) 566-7805. e-mail: shernan@hsph.harvard.edu This work was supported by a pilot project grant from Harvard’s National Institute of Environmental Health Sciences Center in Environmental Health (ES00002) and by grants ES009718 and OH008578. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. S.H.-D. and A.A.M. have received unrestricted research and training grants and contracts from pharmaceutical companies for unrelated projects, some of which manufacture drugs discussed in this article. No support for the analyses was provided by funding from these companies, and they were not aware of the project. Received 5 June 2008 ; accepted 7 October 2008.
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