Error in diagnosis and medication prescription in a psychiatric patient with a history of hypothyroidism: A case report

This article reports a case of a medical error in the diagnosis and treatment of thyroid disease in a 29-year-old man hospitalized following a suicide attempt and diagnosed with severe depression. The patient had a history of hypothyroidism managed with levothyroxine. During his hospitalization, abnormal liver and kidney test results prompted an internal medicine consultation for further evaluation. The specialist mistakenly interpreted the patient’s TSH level as 0.2 mIU/L (instead of 2.0), diagnosed hyperthyroidism, and prescribed methimazole. Although the drug was not available in the hospital pharmacy, the patient received methimazole the day before discharge, which he took concurrently with levothyroxine. Upon review of the patient’s file, the ward pharmacist identified this drug interaction and contacted the patient to discontinue methimazole. This case clearly illustrates diagnostic and therapeutic errors caused by incorrect test interpretation, poor coordination in medication management, and insufficient clinical supervision. The study explores the possible causes of these errors, emphasizes the importance of clinical decision support systems, highlights the need for ongoing staff training in thyroid test interpretation, and underscores the crucial role of pharmacists in preventing medication errors.