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Effect of Age, Weight and Sex on Levothyroxine Pharmacokinetics

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ClinicalTrials.gov Identifier: NCT03102177
Recruitment Status : Completed
First Posted : April 5, 2017
Last Update Posted : April 6, 2017
Sponsor:
Information provided by (Responsible Party):
Georgetown University

Brief Summary:
This study was a prospective, single-center, open-label, non-randomized, pharmacokinetic study using stable isotope carbon-13 labeled levothyroxine

Condition or disease Intervention/treatment Phase
Hypothyroidism Primary Drug: Administration of stable Isotope labeled levothyroxine Early Phase 1

Detailed Description:

Setting The study was conducted on the clinical research unit of an academic medical center.

Participants Adults of any age being treated with levothyroxine for hypothyroidism were studied.

Interventions A single dose of 13C- LT4 was administered to hypothyroid subjects taking levothyroxine replacement.

Main Outcomes and Measures Eighteen serial plasma samples were collected. One sample was obtained before the 13C- LT4 dose and the remainder over the 312-hour period post-dosing. 13C- LT4 concentration was quantified using validated liquid chromatography tandem mass spectrometry methods. Pharmacokinetic analysis was conducted using linear log trapezoidal non-compartmental analysis using Phoenix 6.4.


Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 41 participants
Intervention Model: Single Group Assignment
Intervention Model Description: Open label prospective study
Masking: None (Open Label)
Primary Purpose: Other
Official Title: Hypothyroidism Treatment in Aging and Thyroid Cancer
Actual Study Start Date : May 31, 2011
Actual Primary Completion Date : November 30, 2013
Actual Study Completion Date : July 26, 2016

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Hypothyroidism

Arm Intervention/treatment
Experimental: Stable isotope arm
Measurement of blood levels of labelled levothyroxine after administration of single oral dose of stable isotope levothyroxine
Drug: Administration of stable Isotope labeled levothyroxine
Administration of single dose of stable isotope carbon-13 labeled levothyroxine and measurement of blood levels of stable isotope-labeled levothyroxine
Other Name: levothyroxine or synthroid




Primary Outcome Measures :
  1. CL/F [ Time Frame: 120 hours ]
    oral clearance rate (defined as the ratio of dose administered to AUC0-∞)

  2. V/F [ Time Frame: 120 hours ]
    apparent volume of distribution (estimated by CL/F/ λ)

  3. t-half [ Time Frame: 120 hours ]
    the half-life of the terminal disposition phase (t-half) estimated by ln(2)/λ .


Secondary Outcome Measures :
  1. CL/F analysed by age groups [ Time Frame: 120 hours ]

    CL/F will be compared in adults (age ≤60 years) versus elderly (age>60 years) using Wilcoxon signed-rank test using significance level of α = 0.05. Additionally, these PK parameters were regressed against age (as a continuous covariate).

    Sex (male or female), weight (as a continuous covariate), and body mass index (BMI) (as a continuous covariate) will be considered using a stepwise linear regression approach.


  2. V/F analysed by age groups [ Time Frame: 120 hours ]

    V/F will be compared in adults (age ≤60 years) versus elderly (age>60 years) using Wilcoxon signed-rank test using significance level of α = 0.05. Additionally, these PK parameters were regressed against age (as a continuous covariate).

    Sex (male or female), weight (as a continuous covariate), and body mass index (BMI) (as a continuous covariate) will be considered using a stepwise linear regression approach.


  3. t-half by age groups [ Time Frame: 120 hours ]

    t-half will be compared in adults (age ≤60 years) versus elderly (age>60 years) using Wilcoxon signed-rank test using significance level of α = 0.05. Additionally, these PK parameters were regressed against age (as a continuous covariate).

    Sex (male or female), weight (as a continuous covariate), and body mass index (BMI) (as a continuous covariate) will be considered using a stepwise linear regression approach.




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Ages Eligible for Study:   21 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Gender Based Eligibility:   Yes
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • age >21 years at the time of consent
  • euthyroidism while undergoing treatment with LT4
  • no other serious illness
  • ability to give written informed consent.

Exclusion Criteria:

  • baseline hematocrit lower than 28.0%
  • TSH greater than 4.5 mIU/L
  • kidney dysfunction
  • concomitant use of drugs that affect thyroidal axis interactions

Responsible Party: Georgetown University
ClinicalTrials.gov Identifier: NCT03102177     History of Changes
Other Study ID Numbers: 2010-572
First Posted: April 5, 2017    Key Record Dates
Last Update Posted: April 6, 2017
Last Verified: March 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No

Additional relevant MeSH terms:
Hypothyroidism
Thyroid Diseases
Endocrine System Diseases