Urinary phthalate metabolite concentrations among men with inflammatory bowel disease on mesalamine therapy.
BACKGROUND
Phthalates, a family of compounds used in a variety of consumer products, are reproductive and developmental toxicants in experimental animals. One of these phthalates, dibutyl phthalate (DBP), is an inactive ingredient in the coating of Asacol.


OBJECTIVE
To determine if men with inflammatory bowel disease taking Asacol have higher urinary concentrations of monobutyl phthalate (MBP), a metabolite of DBP, compared to the general population in the United States.


METHODS
Five patients at the Massachusetts General Hospital Crohn's and Colitis Center, taking at least 800 mg of Asacol three times a day, provided one spot urine sample. Urinary MBP and other phthalate metabolite concentrations were measured by using online solid phase extraction coupled with isotope dilution high-performance liquid chromatography tandem mass spectrometry.


RESULTS
In four of the five men, the urinary concentrations of MBP (9888 ng/mL, 12,308 ng/mL, 10,124 ng/mL, and 41,590 ng/mL) and of a minor DBP metabolite, mono(3-carboxypropyl) phthalate (MCPP, 116.4 ng/mL, 163.4 ng/mL 72.6 ng/mL, 5604 ng/mL) were orders of magnitude higher than the background concentrations among the US general population. One subject missed his morning Asacol dose and had urinary MBP concentrations (17.5 ng/mL) similar to background levels.


CONCLUSIONS
We confirmed that men with inflammatory bowel disease taking Asacol have urinary concentrations of MBP and MCPP much higher than background levels.
Division of Gastroenterology, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA.
Elizabeth J
EJ
Hait
National Center for Environmental Health, Centers for Disease Control and Prevention, Boston, MA, USA.
Antonia M
AM
Calafat
Department of Environmental Health, Harvard School of Public Health, Boston, MA, USA ; The Fertility Center, Vincent Memorial Obstetrics and Gynecology, Massachusetts General Hospital, Boston, MA, USA.
Russ
R
Hauser
Asacol; endocrine disruptor; phthalate