Low-dose captopril titration in patients with moderate-to-severe hypertension treated with diuretics

To study the value of low-dose captopril (6.25 and 12.5 mg) and a diuretic combination, the blood pressure and heart rate of 17 patients with moderate-to-severe hypertension were monitored for 6 hours (hospital) or 3 hours (office) after the single low-dose or larger (25, 50, 100 and 150 mg) captopril dosage. All patients had preserved renal function and were taking an oral diuretic (hydrochlorothiazide or furosemide) for at least 4 weeks. The supine and upright acute blood pressure lowering with 6.25 mg was not different from the larger captopril doses; none produced persistent or profound hypotension. There was no deterioration of renal function, new or persistent increase in proteinuria, neutropenia or agranulocytosis acutely or during 17 +/- 2 weeks of follow-up. Low-dose captopril (6.25 or 12.5 mg three times daily) normalized the supine blood pressure of 35% of these patients acutely. We suggest that in hypertensive patients already taking a diuretic, a lower starting dose of captopril than the recommended 25 mg three times daily may be desirable.