Once daily dosing of enalapril in congestive heart failure

Enalapril 40 mg or tolerated dose was given once daily to 21 patients with congestive heart failure (CHF), NYHA class III, in addition to treatment with digoxin and/or diuretics. After an 8-week open period, 19 patients were randomized to continue enalapril or to receive a placebo in a double-blind manner. After the first enalapril dose of 10 mg, maximal reduction of blood pressure (BP) occurred after 4 hours (mean 34/17 mmHg; p less than 0.001). No further reduction was found after higher doses. After the open period significant improvement was shown as judged by NYHA class (p less than 0.01), stroke volume (p less than 0.05), maximal working capacity (p less than 0.05), heart volume (p less than 0.01) and maximum rate pressure product (RPPmax) (p less than 0.001). Urinary aldosterone markedly decreased (p less than 0.01), whereas serum potassium and serum creatinine slightly increased (p less than 0.05). At the end of the blind period enalapril was superior to placebo concerning NYHA class (p less than 0.01), heart volume (p less than 0.05) and RPPmax (p less than 0.05). Other parameters, including aldosterone in urine, did not differ between the groups. Carry-over effects may have diminished the differences between enalapril and placebo. Diarrhoea (n = 5) and hypotension (n = 5) were the most common side-effects. Overall, enalapril was well tolerated and seems to be useful in single daily doses in the treatment of CHF.