Stable Isotope Pharmacokinetic Studies Provide Insight into Effects of Age, Sex, and Weight on Levothyroxine Metabolism.

ABSTRACT: BACKGROUND:This study sought to determine whether levothyroxine pharmacokinetics (PKs) are affected by age, weight, and sex. METHODS:A PK study was performed after administration of a tracer dose of carbon-13-labeled LT4 (13C-LT4). The study was conducted at an academic medical center. Adults of any age being treated with levothyroxine for hypothyroidism were enrolled in the study. A single dose of 13C-LT4 was administered. Eighteen serial plasma samples were collected. One sample was obtained before the 13C-LT4 dose, and the majority of the remaining samples were collected over the 120-hour period post dosing. 13C-LT4 concentration was quantified using liquid chromatography tandem mass spectrometry. PK analysis was conducted using a linear log trapezoidal non-compartmental analysis using

SUBMITTER: Younis IR 

PROVIDER: S-EPMC5770123 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature