How do thiazide diuretics cause hypercalcemia?

Answer 1

In the kidney, the DCT reabsorbs about 8% of the filtered Ca2+ load. This occurs via epithelial Ca2+ channels. In the steady state, the cell must extrude all entered Ca2+, which occurs via a Ca2+ ATPase, and also through Na+/Ca2+ exchanger located on the BASOLATERAL surface of the cells of the distal tubule. Thiazides inhibit the Na+/Cl- symport in the early DCT, thus causing a decrease in INTRAcellular Na. This, in turn, enhances the activity of the Na+/Ca2+ exchanger, creating an increased driving for Ca 2+ resorption through the epithelial Ca2+ chnnels. The final effect: increased Ca2+ reabsorption that can cause hypercalcemia or more often, unmask hypercalcemia due to other causes. ie; maligancy

Answer 2

By competing with the secretion of uric acid via the Organic Acid Transporter in the proximal tubule.