Effect of once weekly oral levothyroxine therapy

SUMMARY: Primary hypothyroidism is one of the most common endocrine disorders with widely available treatment. A minority of patients remain with uncontrolled hypothyroidism despite therapy. The objective of this case series was to demonstrate that medication non-adherence, rather than malabsorption, should be sought as the most common cause of unsuppressed TSH levels in patients receiving treatment for this condition. Non-adherence is often considered as a diagnosis of exclusion. Nonetheless, a diagnosis of malabsorption requires a more extensive workup, including imaging and invasive procedures, which increase healthcare costs and burden to the patient. The findings of this study allow for a cost-effective approach to uncontrolled hypothyroidism. LEARNING POINTS: Medication non-adherence is a common cause of insuppressible TSH levels. Once weekly levothyroxine is an alternative approach to non-compliant patients. Assessing compliance is more cost-effective and less burdensome than testing for malabsorption.