Approximately one-third of older patients treated with thyroid hormones report concomitant medication use that may interfere with the accuracy of thyroid function tests, which may lead to thyroid failure. influencing treatment decisions, a new study shows.
“We know from previous studies that thyroid hormone use is common in older adults and that there are many medications that can interfere with thyroid function tests in a variety of ways,” he said. senior author Maria Papaleontiou, MD. Medscape Medical News.
“However, to our knowledge, the level of concomitant use of thyroid hormones and the uptake of medications in older adults, age 65 years and older, has not been previously studied,” said Papaleontiou, of the Department of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor.
The findings were presented as a poster during the landmark ENDO 2021, the annual meeting of the Endocrine Society.
Commenting on the study, Thanh Duc Hoang, DO, an endocrinologist with the Walter Reed National Military Medical Center, in Silver Spring, Maryland, said: “It is important for clinicians to be aware of various interactions and interventions of medications that affect the accuracy of thyroid function tests. “
“If patients are unable to stop the medications shortly before the blood transfusion, the clinicians may consider prescribing different thyroid tests or assessments that avoid the intervention,” he said. Medscape Medical News.
32% of patients who take coins may take tests
In evaluating data on 538,137 patients treated with thyroid hormones from Veterans Health Administration Corporate Data Warehouse, spanning 2004-2017, first author Rachel Beeson, MD, and colleagues with the University of Michigan found the majority of patients in the study were male (96.5%), White (77.1%), and had two or more joints (62.6%).
Of this total, 170,261 patients (31.6%) treated with thyroid hormones, over a median follow-up of 56 months, were taking at least one drug that could interfere with thyroid function tests.
Among drugs with potential thyroid test intervention, approximately 28% of patients were taking prednisone or prednisolone, 8% were taking amiodarone, and 1.42% were taking phenytoin. Other drugs reported to be potentially inhibitory include carbamazepine (0.91%), phenobarbital (0.15%), lithium (0.40%), and tamoxifen (0.11%).
Multivariate analysis showed that traits associated with those most likely to use concomitant medication included non-whites (OR, 1.18 vs. Whites), Hispanic ethnicity (OR, Whites). OR 1.11 vs. non-Hispanic), female gender (OR 1.12 vs. male), and the presence of comorbidities (e.g., Charlson-Deyo comorbidity score ≥ 2, OR, 2.47 vs. 0 score).
At the same time, older patients aged 85 years or older had a lower likelihood that concomitant medications would affect thyroid tests (OR, 0.47 vs. 65–74 years).
The findings are worrying regarding the widespread use of levothyroxine to treat hypothyroidism, the most widely prescribed drug in the United States.
“Our findings not only highlight the complexity of thyroid hormone regulation in older adults in the context of polypharmacy and multimorbidity, but also draw people’s attention to vulnerable groups for this practice, which included female patients, non-Whites, patients of Hispanic descent, and patients with comorbidities, “Papaleontiou said.
The Nature of Intervention of Different Abilities
Medications or medications can block thyroid function tests in a number of ways, she explained. “Some medications may lead to a reduction in levothyroxine uptake, others may affect how well the pill dispenses.”
In addition, certain medications can affect the circulation of thyroid hormone in the blood and how it binds to proteins, or they can lead to reduced thyroid hormone levels as a result of a number of interactions.
And by contrast, “What ‘s even more challenging is that certain medications or medications are likely to affect thyroid activity based on laboratory tests when they are not in use. actually affect thyroid activity and could lead to unnecessary dose changes, ”Papaleontiou noted.
Recommendations against prevention
Routine recommendations to try to counteract the effects of polypharmacy on thyroid treatment include advising patients to take thyroid hormones on an empty stomach at least 30-60 minutes before eating to catch them. better.
If the patient is taking medications that are known to inhibit the uptake of thyroid hormones, the recommendation is to discontinue those within at least 4 hours.
“The big challenge in older adults is that many of them experience polypharmacy, being at risk for drug-drug reactions,” Papaleontiou said.
“Physicians and patients should be vigilant and communicate closely each time a new medication or drug is initiated to consider the presence of an intervention.”
The authors did not report any material financial relationships. Hoang has stated that he is a spokesperson for Acella Pharmaceuticals.
ENDO 2021. Summary P51-1. Presented March 20, 2021.
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