Microalbuminuria in essential hypertension. Reduction by different antihypertensive drugs

The effects of four different antihypertensive drugs (the Ca(2+)-channel blocker felodipine, the beta-blocker metoprolol, the angiotensin converting enzyme inhibitor ramipril, and the alpha-blocking agent doxazosin) on microalbuminuria and renal hemodynamics were evaluated in a double-blind, crossover study in 17 patients (10 women, seven men, aged 39 +/- 14 years) with mild-to-moderate essential arterial hypertension and microalbuminuria. Patients were studied after a 2-week placebo phase preceded by 2 weeks off all medication and after 12 weeks of treatment with each drug. Between each drug treatment, there was another 14-day placebo washout period. At the end of the study, we performed two additional 2-week placebo periods. After each placebo and treatment period, we measured albumin excretion during a 3-day collecting period. Renal hemodynamics were assessed by clearance techniques (inulin and p-aminohippurate clearance) at the end of the first and last placebo periods and after each treatment period. All drugs reduced mean arterial pressure and microalbuminuria to a similar and statistically significant (p < 0.05) extent (mean arterial pressure: placebo phase, 116 +/- 5 mm Hg; felodipine, 101 +/- 4 mm Hg; metoprolol, 101 +/- 5 mm Hg; ramipril, 101 +/- 4 mm Hg; doxazosin, 102 +/- 5 mm Hg; urinary albumin excretion: placebo phase, 46 +/- 50 mg/day; felodipine, 18 +/- 23 mg/day; metoprolol, 14 +/- 12 mg/day; ramipril, 16 +/- 16 mg/day; doxazosin, 14 +/- 14 mg/day). Mean arterial pressure levels and urinary albumin excretion returned to baseline after the last placebo period (110 +/- 6 mm Hg and 40 +/- 46 mg/day, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)