Chlorthalidone in Hypoparathyroidism

To the Editor: Porter et al.¹ recently reported in the Journal their experience using chlorthalidone in the management of hypocalcemic, hypoparathyroid patients. In their discussion they state, “…our studies show parathyroid hormone is not required for a thiazide-like diuretic to exert its effect.” Although it is unstated, the implied conclusion by these authors is that the increase in the serum calcium achieved in their patients treated with chlorthalidone was independent of any effect of parathyroid hormone. Yet there is no mention of the parathyroid hormone levels in any of their experimental subjects. Documentation of their patients’ parathyroid hormone concentrations is.