Indapamide in the treatment of essential arterial hypertension: results of a controlled study.

A double-blind trial was carried out in 24 patients with mild hypertension to compare the efficacy and tolerability of indapamide with that of a standard thiazide diuretic, hydrochlorothiazide. After a 6-week washout period on placebo, patients received either 2.5 mg indapamide or 50 mg hydrochlorothiazide per day for 12 weeks. Blood pressure and pulse rate in the recumbent and upright positions were monitored at regular intervals. Laboratory measurements of plasma electrolytes, other biochemical and haematological parameters were made before and after active treatment. The results showed that indapamide treatment produced a statistically significant reduction from placebo levels in diastolic pressure in both the upright and recumbent positions, whereas the reduction was significant only in the upright diastolic pressure with hydrochlorothiazide. There were no significant changes in pulse rate in either active-treatment period. Both drugs produced small but significant reductions in mean plasma chloride and potassium levels, and there was a significant increase in mean serum uric acid in patients receiving hydrochlorothiazide. None of these changes, however, were of clinical importance and all of the patients completed the study.