A 40-year-old man presents with thirst and lethargy, with a blood pressure of 140/90mmHg and corrected calcium of 3.7mmol/l. What is the most appropriate management at this stage?

In the context of the clinical presentation involving thirst, lethargy, elevated blood pressure, and corrected calcium levels of 3.7mmol/l, the most appropriate management is the administration of intravenous fluids.

When a patient presents with hypercalcemia (high levels of calcium in the blood), it’s crucial to first address the potential complications arising from this condition, such as dehydration or renal impairment. Intravenous fluids help to restore hydration, promote urinary excretion of calcium, and directly lower serum calcium levels. This is particularly important as hypercalcemia can lead to a range of symptoms including lethargy, fatigue, and changes in mental status, as seen in this patient.

While certain medications may be indicated in the longer-term management of the underlying causes of hypercalcemia, such as bisphosphonates or calcitonin, the immediate need in this situation is to ensure adequate hydration and reduce the calcium levels in order to mitigate symptoms and prevent further complications. Therefore, the initiation of IV fluids is the most appropriate initial step in the management of this patient.