Treatment-refractory hypothyroidism

Abstract

Practice CMAJ• When levothyroxine requirements exceed 2.5 µg/kg daily, treatmentrefractory hypothyroidism is a possibility.• A supervised test for the absorption of oral levothyroxine can exclude patient nonadherence to the medication.• The results of investigations for causes of decreased absorption of or increased demand for levothyroxine will guide treatment.

Thyroid disorders and gastrointestinal and liver dysfunction: A state of the art review

“…Also, a gluten-free diet has been reported to aid AITD with either levothyroxine dose reduction or amelioration of hypothyroidism [39]. Indeed, coeliac disease as well as other malabsorptive and maldigestive conditions is the commonest cause of treatmentrefractory hypothyroidism (after non-concordance and incorrect administration are excluded) [40].…”

Levothyroxine Treatment of Pregnant Women with Hypothyroidism: Retrospective Analysis of a US Claims Database

“…The reason for this finding is unknown, yet it may reflect the current complexities of treating hypothyroidism in pregnancy as well as the fact that there is no consensus on treating subclinical hypothyroidism in pregnancy [33], possibly because of the increased risk of pregnancy-related adverse outcomes offsetting risk reductions in pregnancy loss [34]. Pregnant patients with high TSH despite levothyroxine therapy may be taking too low a dose, since dose requirements increase over the course of a pregnancy [35], or some portion of patients may have treatmentrefractory hypothyroidism, which can be caused by poor adherence, interactions between the levothyroxine and food, problems with digestion or absorption, autoimmune processes or other conditions [36,37]. The lack of monitoring found for a significant portion of our study population further complicates identification and treatment of these issues.…”

Levothyroxine absorption test in the management of a patient with persistent hypothyroidism

“…The improvement of doctor-patient relationship is very important 2 . To improve the state of hypothyroidism two main prescriptions are possible: supervised weekly thyroxine replacement (the total weekly dose of LT4 given once per week) or parenteral administration (intramuscular or intravenous) of levothyroxine 3,14 .…”