Levothyroxine Absorption Test Followed by Directly Observed Treatment on an Outpatient Basis to Address Long-term High Thyrotropin Levels in a Hypothyroid Patient: a Case Report

Background: For the treatment of hypothyroidism, patients are usually placed on lifelong levothyroxine replacement therapy. Achieving clinical and biochemical euthyroid status is sometimes difficult because of several factors, including poor compliance or poor absorption of levothyroxine in the gut mucosa.

Case Presentation: We present the case of a 45-year-old South Asian female with hypothyroidism on lifelong levothyroxine replacement. However, on her multiple follow-up visits over the past 2 years, it was noted that her thyrotropin level was never controlled and was not in range. A thorough history was unyielding in terms of compliance regarding levothyroxine medication and use of over-the-counter pills or mineral supplements that may interfere with the absorption of levothyroxine. Hence, we performed levothyroxine absorption test to rule out any malabsorption as well as document pseudo-malabsorption favoring drug nonadherence. Levothyroxine absorption test resulted in more than 56% absorption of levothyroxine; therefore, the patient was put on weekly directly observed treatment strategy resulting in normalization of thyrotropin levels on successive follow-ups.

Conclusion: Directly observed treatment to replace levothyroxine once a week can be used as an alternative by health care professionals in patients in whom compliance to daily levothyroxine is the hidden cause of persistently raised thyrotropin. This strategy can reduce undue health burden on the patient and improve adherence to self-medication under confident supervision of the treating physician.