Concurrent Use of Thyroid Hormone Therapy and Interfering Medications in Older US Veterans

Risks of suboptimal and excessive thyroid hormone replacement across ages

BACKGROUND

Hypothyroidism is prevalent at all ages and represents a non-communicable disease with preventable consequences.

METHOD

Narrative review.

REVIEW

In children and adolescents, the most devastating consequences of undertreatment with levothyroxine (LT4) are poor growth and development. Delayed treatment in congenital hypothyroidism can lead to permanent brain damage. In young to middle-aged adults, symptoms are often overlooked, and treatment delayed by many years. The resulting consequences are also at this age group compromised brain and physical function but less severe and partly reversible with treatment. The under-treated condition often results in a higher risk of, e.g., increased cardiovascular disease burden, obesity, hypertension, poor physical capacity, and poor quality of life. Excessive replacement is at all adult age groups associated with increased risk of cardiac death, osteoporosis, loss of muscle function, psychological instability and poor quality of life. In young fertile women, the consequences of undertreatment with LT4 are subnormal fertility, recurrent pregnancy loss, compromised fetal growth, and neurocognitive development. On the other hand, excessive LT4 treatment has been related to gestational hypertension, preeclampsia and preterm birth. In the elderly, care must be given to avoid confusing a slightly high age-related serum TSH with requirement for LT4 treatment in a truly hypothyroid patient. Excessive LT4 treatment in patients of high age is associated with an increased mortality.

CONCLUSION

Suboptimal and excessive LT4 replacement of the preventable non-communicable disease hypothyroidism requires more focus from the healthcare system and from the global political systems to prevent the personally devastating and socioeconomically challenging consequences.

Consequences of undertreatment of hypothyroidism

PURPOSE

To provide an overview of consequences of undertreatment with levothyroxine (LT4) in the common non-communicable disease, hypothyroidism.

METHODS

Narrative review of the literature.

RESULTS

Hypothyroidism is globally very prevalent at all age groups and represents a non-communicable disease in which the risks and consequences are preventable. In children and adolescents, the most devastating consequences of undertreatment are poor growth and development. Lack of early treatment in congenital hypothyroidism can lead to permanent damage of brain function. In young to middle-aged adults, consequences are often overlooked, and treatment delayed by many years. The resulting consequences are also at this age group compromised brain and physical functioning but less severe and partly reversible with treatment. The undertreated condition often results in a higher risk of several secondary devastating diseases such as increased cardiovascular disease burden, obesity, hypertension, poor physical capacity, poor quality of life. In young women of fertile age the consequences of undertreatment with LT4 are subnormal fertility, recurrent pregnancy loss, preeclampsia, compromised fetal growth and neurocognitive development. There is a further risk of 30-50% of developing postpartum thyroiditis. In the elderly population care must be given to avoid confusing a slightly high serum TSH as result of physiological age adaptation with a requirement for LT4 treatment in a truly hypothyroid patient.

CONCLUSION

Undertreatment of the preventable non-communicable disease hypothyroidism requires more focus both from caretakers in the healthcare system, but also from the global political systems in order to prevent the personally devastating and socioeconomically challenging consequences.

Management of thyroid dysfunction and thyroid nodules in the ageing patient

Thyroid dysfunction is a common endocrine disorder in the general population, with a reported prevalence of 10-15%. However, this rate is even higher in older adults, with an estimated prevalence of ≈25% in some populations. Since elderly patients usually present more comorbidities than younger individuals, thyroid dysfunction may carry a synergistic negative health impact, mainly due to increased cardiovascular disease risk. Moreover, thyroid dysfunction in the elderly can be more difficult to diagnose due to its subtle or even asymptomatic clinical presentation, and the interpretation of thyroid function tests may be affected by drugs that interfere with thyroid function or by the coexistence of several diseases. On the other hand, thyroid nodules are also a prevalent condition in older adults, and its incidence increases with age. The assessment and management of thyroid nodules in the ageing patient should take into account several factors, as risk stratification, thyroid cancer biology, patient´s overall health, comorbidities, treatment preferences, and goals of care. In this review article, we summarize the current knowledge on the pathophysiology, diagnosis, and therapeutic management of thyroid dysfunction in elderly patients and we also review how to identify and manage thyroid nodules in this population.

Concomitant use of levothyroxine and interacting medications in U.S. ambulatory care visits

BACKGROUND

Levothyroxine (LT4) is the third most commonly prescribed medication in the United States. It is a narrow therapeutic index medication, and thus can be impacted by drug-drug interactions, which are primarily available over-the-counter. The prevalence and associated factors with concomitant interacting drugs with LT4 is limited since over-the-counter products are not routinely captured in many drug databases.

OBJECTIVE

This study aimed to characterize the concomitant use of LT4 with interacting drugs at ambulatory care visits in the United States.

DESIGN

A cross-sectional analysis of the National Ambulatory Medical Care Survey (NAMCS) from 2006 to 2018 was completed.

SETTING AND PARTICIPANTS

Ambulatory care visits in the United States involving adult patients with a LT4 prescription were included in the analysis.

OUTCOME MEASURES

The primary outcome was initiation or continuation of a selected concomitant interacting drug which impacts LT4 absorption (e.g., proton pump inhibitor) in a patient visit in conjunction with LT4.

RESULTS

The authors analyzed 372,942,000 visits (weighted from a sample of 14,880) with a reported LT4 prescription. Concomitant use of interacting drugs with LT4 occurred in 24.4% of visits in which 80% of interacting drugs were proton pump inhibitors. Ages 35-49 years (adjusted odds ratio [aOR], 1.59), 50-64 years (aOR, 2.27), and ≥65 years (aOR, 2.87) compared to 18-34 years, female (aOR 1.37) versus males, and visits in 2014 or later (aOR, 1.27) versus 2006-2009 were associated with increased odds of concomitant interacting drug use in multivariable analysis.

CONCLUSION

At ambulatory care visits between 2006 and 2018, concomitant use of LT4 and interacting drugs impacted one-quarter of patient visits. Increased age, females, and visits later in the study period were associated with increased odds for concomitant interacting drugs. Additional work is needed to identify downstream consequences of concomitant use.

Towards De-Implementation of low-value thyroid care in older adults

PURPOSE OF REVIEW

This review discusses the current literature regarding low-value thyroid care in older adults, summarizing recent findings pertaining to screening for thyroid dysfunction and management of hypothyroidism, thyroid nodules and low-risk differentiated thyroid cancer.

RECENT FINDINGS

Despite a shift to a "less is more" paradigm for clinical thyroid care in older adults in recent years, current studies demonstrate that low-value care practices are still prevalent. Ineffective and potentially harmful services, such as routine treatment of subclinical hypothyroidism which can lead to overtreatment with thyroid hormone, inappropriate use of thyroid ultrasound, blanket fine needle aspiration biopsies of thyroid nodules, and more aggressive approaches to low-risk differentiated thyroid cancers, have been shown to contribute to adverse effects, particularly in comorbid older adults.

SUMMARY

Low-value thyroid care is common in older adults and can trigger a cascade of overdiagnosis and overtreatment leading to patient harm and increased healthcare costs, highlighting the urgent need for de-implementation efforts.