A 40-year-old man complains of thirst and lethargy with serum calcium of 3.5 mmol/l. What is the most appropriate initial management?

In this scenario, the patient is presenting with symptoms indicative of hypercalcemia, as evidenced by the elevated serum calcium level of 3.5 mmol/l, which is significantly above the normal range. Initial management in cases of hypercalcemia, especially when accompanied by symptoms like thirst and lethargy, primarily focuses on rehydration to help lower serum calcium levels and restore normal physiological function.

Administering intravenous fluids is crucial because it helps dilute the calcium concentration in the blood and promotes renal excretion of excess calcium. This is particularly important in symptomatic hypercalcemia where immediate intervention is needed to alleviate symptoms and prevent complications such as renal dysfunction or cardiac arrhythmias.

While other treatments like calcitonin can help inhibit osteoclastic bone resorption and may be used in specific situations, they are not the first-line management in acute symptomatic hypercalcemia. Similarly, IV hydrocortisone is indicated in cases of adrenal insufficiency or certain types of hypercalcemia associated with malignancies but is not the primary treatment for acute hypercalcemia itself.

Furosemide can promote renal excretion of calcium, and while it may be used after volume repletion, initiating treatment with it before adequate hydration is not advisable due to the risk of