Tablet formulation of levothyroxine is absorbed less well than powdered levothyroxine
Abstract
The comparative bioavailability of oral doses of levothyroxine (LT(4)) formulation taken as tablets, after being crushed, or chewed before swallowing has not been well studied. Three patients with hypothyroidism who showed persistent elevation of serum thyrotropin (TSH) despite taking 200, 150, and 125 microg of LT(4) tablets per day are presented. They did not show signs and symptoms of gastrointestinal illness that could interfere with the absorption of LT(4) nor history of such a condition. They did not concurrently take medications known to affect the absorption of LT(4) from the gut. Their serum TSH levels normalized when the tablets were taken after being pulverized. The difference appeared attributable to the slow dissolution of the tablets in the gut of these patients.
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Pulverized LT4 tablets were better absorbed than the entire tablet.
“Pulverized LT4 tablets were better absorbed than the entire tablet (18).”
From Levothyroxine: conventional and novel drug delivery formulations. (2023) · cites this paper as [18]
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- Authors
- Yamamoto, T.
- Affiliations
- Yamamoto Naika, Chuo-ku, Osaka, Japan.
- Corresponding author
- Yamamoto, Toshihide
- ORCID
- Yamamoto, Toshihide
- Venue
- Thyroid
- Publisher
- SAGE Publications
- Published
- 2003-12
- Volume
- 13
- Issue
- 12
- Pages
- 1177-1181
- ISSN
- 1050-7256 (ISSN-L)
- 1557-9077
- OpenAlex
- W2118213544
- Cited by
- 21
- References
- 22
- Citations by year
- 2025: 1 · 2023: 2 · 2022: 3 · 2021: 1 · 2020: 1 · 2019: 3 · 2016: 2 · 2015: 1 · 2014: 1 · 2013: 1 · 2012: 1
- FWCI
- 0.00
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Thyroid (publishedVersion)
- PubMed (publishedVersion)
- Funders
- Abbott Laboratories
- Abbott Japan
- Topics
- Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Thyroid Disorders and Treatments
- Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmaceutical Science › Drug Solubulity and Delivery Systems
- Health Sciences › Medicine › Surgery › Thyroid and Parathyroid Surgery
- Keywords
- levothyroxine, tablet formulation, drug absorption, bioavailability, hypothyroidism, thyroid-stimulating hormone, tablet dissolution, crushed tablets, antithyroid drug therapy
- MeSH terms
- Adult, Biological Availability, Congenital Hypothyroidism, Dose-Response Relationship, Drug, Female, Humans, Hypothyroidism, Intestinal Absorption, Male, Middle Aged, Powders, Tablets, Thyrotropin, Thyroxine
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