Effect of indapamide on the renin-aldosterone system, and urinary excretion of potassium and calcium in essential hypertension.

The effect of indapamide, 2.5 mg daily, on blood pressure, electrolyte balance and the renin-aldosterone system was studied in 11 patients with essential hypertension. During indapamide treatment blood pressure decreased and the renin-aldosterone system was stimulated. A moderate hypokalaemia seen during indapamide treatment was not correlated to changes in plasma aldosterone concentration. Fractional excretion of potassium was unchanged during treatment, while renal calcium excretion was reduced. No effect on calcium in serum was observed.