Efficacy and Safety of Losartan in Patients with Proteinuria

The renoprotective effect and safety of an angiotensin II receptor blocker, losartan, were studied in 11 diabetic and 14 nondiabetic patients with a daily urinary protein excretion >500 mg. Once-daily losartan was administered to all patients for 16 weeks without diuretics or other antihypertensive agents. A daily dose of 50 mg was given to those patients with a sitting systolic blood pressure of between 130 and 170 mm Hg; 25 mg was given to patients with a systolic blood pressure of between 110 and 130 mm Hg. Sixteen patients (6 diabetic and 10 nondiabetic patients) had a more than 25% decrease of their daily urinary protein excretion (response rate 64%). The mean decrease in these 16 patients was 57 +/- 17% (p < 0.05). Two patients (1 diabetic and 1 nondiabetic) had more than a 25% increase of their urinary protein excretion. The trough sitting systolic blood pressure of all patients (n = 25) decreased from 142 +/- 17 to 125 +/- 13 mm Hg (p < 0.05) and the trough sitting diastolic blood pressure from 87 +/- 11 to 78 +/- 11 mm Hg (p < 0.05). Serum uric acid was measured in 16 patients; a decrease from 7.3 +/- 1.6 to 6.6 +/- 1.4 mg/dl (a 9.6% decrease, p < 0.05) was found after 16 weeks. Our study showed that in both diabetic and nondiabetic proteinuric patients once-daily losartan, given as monotherapy at doses of 25 or 50 mg, was effective in reducing blood pressure, serum uric acid levels, and daily urinary protein excretions.