EFFECTS OF H2 BLOCKERS, PROTON PUMP INHIBITORS AND EZETIMIBE ON THYROXINE ABSORP

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Thyroxine replacement therapy (LT4) is used to treat hypothyroid patients. We plan to examine the effects that histamine 2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs) each have on LT4 absorpition. Also, in our clinical experience, ezetimibe may interfere with LT4 absorption. in our study, at baseline, healthy volunteers will be given a dose of LT4 and undergo successive lab tests over 8 hours to examine the rise of serum thyroid hormone levels. After a washout period of six to eight weeks, these same volunteers will be given either daily doses of an H2RA or a PPI for one week or a single dose of ezetimibe. A single LT4 dose will be administered again at the end of the week, followed by repeat drawing of serum thyroid hormone levels. We will compare thyroid hormones concentrations achieved following LT4 administration to the healthy volunteer at baseline versus after therapy with: a) week long course of an H2RA, b) week long course of a PPI or c) simultaneously administered dose of ezetimibe.