Case Study 3:

Miss C is a 35-year-old teacher, who presents to the polyclinic with unintentional weight loss. Over the past 4 months, she has lost about 7kgs without changes in her lifestyle or diet. She reports a good appetite despite the weight loss. She is feeling more tired and anxious recently, which she attributes to the increasing work stress in her school. She has been feeling hot constantly and sweats easily too. She has no gastrointestinal complaints, except for occasional loose stools. She has no family history of thyroid disorders.

On examination, she looks tired with bulging eyes and a fine tremor upon outstretching of her hands. She is afebrile, her heart rate is 110 beats per minute (with regular rhythm), her blood pressure is 140/80 mmHg and her respiratory rate is 14 breaths per minute. There is a large, smooth, non-tender lump found on her anterior neck.

She is subsequently diagnosed with an endocrine disorder, which she opts to be followed up with by her private doctor. Fast forward 4 years later… Miss C visits the polyclinic again with a different complaint. She has become increasingly tired over the past 1 year. She is unable to stay awake after 8 pm and sleeps through the night with difficulty getting up from bed in the morning! She finds it difficult to concentrate at work with episodes of falling asleep in the office. She also reports constipation and some weight gain. During one direct questioning, she revealed that her endocrine disorder has been “cured” 2 years ago in the private hospital, where she took an oral liquid medicine.

a. What is the MOST likely diagnosis of Miss C’s condition (Please provide only ONE diagnosis and briefly justify your answer).

b. Based on the case study, discuss the etiology (or risk factors), pathogenesis, clinical features, and complications of the diagnosis given in question a.

c. Explain the pharmacotherapy for this diagnosis (include appropriate local drug examples, mechanisms of action, and adverse effects).

d. Based on your answers to question c, explain the MOST possible cause of Miss C’s new presenting symptoms 4 years later.