Severe TSH Elevation and Pituitary Enlargement After Changing Thyroid Replacement to Compounded T4/T3 Therapy.

• Type of Material: Article
• Authors: Adlai L. Pappy, Emory University; Nelson Oyesiku, Emory University; Adriana Ioachimescu, Emory University
• Language: English
• Date: 2016-08-02
• Publisher: SAGE Publications (UK and US): Creative Commons Attribution
• Publication Version: Final Published Version
• Copyright Statement: © 2016 American Federation for Medical Research
• License: Creative Commons Attribution 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1177/2324709616661834
• Title of Journal or Parent Work: Journal of Investigative Medicine High Impact Case Reports
• ISSN: 2324-7096
• Volume: 4
• Issue: 3
• Start Page: 2324709616661834
• End Page: 2324709616661834
• Keywords: compounded T4/T3; levothyroxine; pituitary hyperplasia; hypothyroidism; pituitary enlargement
• Research Categories: Health Sciences, Medicine and Surgery; Biology, Neuroscience

Abstract

We present the first case of iatrogenic hypothyroidism as a result of compounded thyroid hormone (T4/T3) therapy. The thyroid replacement was changed from 175 µg levothyroxine (LT4) to 57/13.5 µg compounded T4/T3 daily in order to improve the T3 level, despite normal thyroid-stimulating hormone (TSH). This resulted in clinical manifestations of hypothyroidism and high TSH level (150 µIU/mL). Six months later, the patient was referred to our clinic for abnormal pituitary magnetic resonance imaging. On reinitiating a physiologic dose of LT4, clinical and biochemical abnormalities resolved and the pituitary gland size decreased. Our case emphasizes the importance of using TSH level to gauge dose adjustments in primary hypothyroidism. Also, it underscores the current American Thyroid Association recommendation against routine use of compounded thyroid hormone therapy.