The Incidence, Investigation and Treatment of Idiopathic Hypercalciuria

Abstract

Summary A hundred and eight patients with renal calculi attending a single clinic were studied in order to try and establish the primary cause of their stones. Sixty‐six of these patients (61 %) proved to have idiopathic hypercalciuria, confirming that this is the most common cause of renal calculi in adult males. A total of 87 patients with idiopathic hypercalciuria were investigated. Plasma calcium was normal with no “tendency to a low plasma calcium”, plasma inorganic phosphate was only 0–5 mg/100 ml below normal, and plasma urate only 0–5 mg/100 ml above normal. The long‐term effect on the urinary calcium of patients with idiopathic hypercalciuria treated with bendrofluazide and/or cellulose phosphate has been studied. The success rate in lowering urinary calcium was 54% for thiazide alone, 60% for cellulose phosphate alone, and 100% in the small number treated with both drugs together. The overall success rate was 75 %, but may yet rise further.