Indapamine effects on hypercalciuria and bone mineral density

Idiopathic hypercalciuria is associated to urinary stone formation and bone loss and should be treated not only to prevent kidney stone formation but also to prevent fragility fractures. Thiazide diuretics are traditionally used to control hypercalciuria. Indapamine, a sulfonamide thiazide diuretic, with some differences in structure is similar in its mechanisms of action such as its hypocalciuric effect, and bone density protection, with less adverse metabolic consequences than thiazides such as less hypokalemia and hypotension. We evaluated efficacy and adverse effects of Indapamine in 88 idiopathic hypercalciuric consecutive patients and those who reached normal calciuria in the first 9 months, were followed during two years. Changes in bone turn-over markers and bone density were evaluated. Since year one, there was a significant lowering of urine calcium to normal values in 77 patients, with no change in sodium excretion. There were changes in bone turn over markers and gains in bone mineral density according to the groups analyzed. In 25 hypercalciuric osteoporotic patients, there was a significant increment in lumbar spine bone density at year 2 of follow-up, (p<0.05). Those hypercalciuric osteoporotic stone former patients had a significant increase in femoral neck bone density since year one. Adverse effects were not significant, no changes found in blood pressure, glycaemia, cholesterol, serum uric acid, sodium and potassium. Two patients needed potassium supplementation for mild hypokalemia and did not stop Indapamine. In conclusion Indapamine is an effective alternative treatment to Idiopathic hypercalciuria, controlling calcium loss and bone density for at least two years.