HealthDay News — Almost one-third of adults aged 65 years and older on thyroid hormone replacement also take medications that commonly interfere with thyroid function tests, according to a study presented at the annual meeting of The Endocrine Society, held virtually from March 20 to 23.
Rachel Beeson, MD, from the University of Michigan in Ann Arbor, and colleagues conducted a retrospective cohort study of 538,137 thyroid hormone users aged 65 years and older to examine concurrent use of thyroid hormone replacement therapy and medications that commonly interfere with thyroid function tests (prednisone, prednisolone, carbamazepine, phenytoin, phenobarbital, amiodarone, lithium, interferon-alpha, and tamoxifen).
The researchers found that during the study period (median follow-up, 56 months), 31.6% of the patients were on at least 1 interfering medication while receiving thyroid hormone replacement therapy. The likelihood of concurrent use of thyroid hormone and interfering medications was increased in association with non-White race vs White race, Hispanic ethnicity compared with non-Hispanic ethnicity, female sex compared with male, and the presence of comorbidities (Charlson-Deyo Comorbidity Score, 2 and over vs 0; odds ratios, 1.18, 1.11, 1.12, and 2.47, respectively). The likelihood of concurrent use of thyroid hormone and interfering medications was reduced in association with older age (e.g., 85 years and older vs 65 to 74 years: odds ratio, 0.47).
“Our findings highlight the complexity of managing thyroid hormone replacement in older adults, many of whom take medications for other medical conditions,” Beeson said in a statement.