One-third of patients remain euthyroid after ending thyroid hormone replacement
More than one-third of individuals taking thyroid hormone replacement remained euthyroid after discontinuing their medication, according to study findings published in Thyroid.
“Our findings suggest that deprescribing levothyroxine, the second most common prescribed medication in the U.S., could be successful for carefully selected patients,” Spyridoula Maraka, MD, MS, assistant professor in the division of endocrinology and metabolism at the University of Arkansas for Medical Sciences, endocrinologist at the Central Arkansas Veterans Healthcare System, and a research collaborator in the knowledge and evaluation research unit of the division of endocrinology, diabetes, metabolism and nutrition at Mayo Clinic in Rochester, Minnesota, told Healio. “These findings also imply that some patients may be overtreated with levothyroxine therapy. Clinicians have to continuously evaluate their patients’ ongoing need for thyroid hormone replacement therapy.”
Maraka and colleagues conducted a meta-analysis of observational studies analyzing patients on thyroid hormone replacement who discontinued treatment and had no restrictions on age or type of hormone replacement. Studies reporting on thyroid function after discontinuation of medication, predictors and procedures related to the discontinuation, the frequency of symptoms and adverse events after discontinuation, and the framework for thyroid hormone discontinuation were included. Studies were obtained through a comprehensive search of bibliographic databases from inception to Feb. 27, 2020.
There were 17 observational studies included in the meta-analysis, of which 16 evaluated thyroid hormone status categorically, eight evaluated thyroid hormone status numerically, and four evaluated clinical symptoms. Levothyroxine was the hormone replacement therapy used in 14 studies.
Sixteen studies with 1,082 participants evaluated the proportion of individuals who remained euthyroid after therapy was discontinued. About 37.2% of participants in all studies were euthyroid at follow-up. The euthyroid estimate was similar for adults at 37.9%, but lower for those who previously had overt hypothyroidism, with only 11.8% remaining euthyroid.
In nine studies evaluating the number of participants who restarted thyroid hormone therapy during follow-up, 65.8% restarted medication over an assessment time ranging from 3 weeks to a median of 5 years. In those who previously had overt hypothyroidism, 87.2% restarted thyroid hormone therapy during follow-up.
Four studies that included mean thyroid-stimulating hormone values showed participants had a mean TSH increase of 9.4 mIU/L from before levothyroxine to after medication stopped. Data on predictors for developing hypothyroidism after levothyroxine withdrawal were insufficient for meta-analysis. No studies used the term deprescribing and none included a systemic process for deprescribing, which Maraka said should be addressed in future research.
“Studies focusing on the process of deprescribing (eg, selection of patients, conversation about deprescribing and deprescribing plan) are needed to support safe and likely beneficial deprescribing of levothyroxine in practice,” Maraka said. “Future research should investigate potential unintended negative consequences of deprescribing for patients, clinicians and health care systems.”
For more information:
Spyridoula Maraka, MD, MS, can be reached at firstname.lastname@example.org.