Hemodynamic comparisons of enalapril and felodipine and their combination.

Thirty-six patients (33 male, 3 female) with a mean age of 67 years and a diastolic blood pressure between 95 and 115 mm Hg, after a four-week placebo run-in period entered a double-blind crossover study comparing felodipine 5 and 10 mg with enalapril 5 and 10 mg and their combination (enalapril 5 mg + felodipine 5 mg). Combined therapy caused a fall in blood pressure of 24/16 mm Hg at trough level that was greater than the falls with the higher doses of monotherapy. The fall with felodipine was greater than with enalapril. Similar patients responded to felodipine and enalapril but more patients achieved blood pressure control with felodipine. When patients not controlled with enalapril 5 mg had felodipine 5 mg or enalapril 5 mg added, felodipine was more effective at lowering blood pressure than the increase in enalapril dosage. A similar effect occurred in those not controlled with felodipine 5 mg. Adverse effects occurred in 22 patients on felodipine, 14 patients on enalapril and 8 on combined therapy. The lipoprotein profile was not altered significantly. Glomerular filtration rates as assessed by 24-hour creatinine clearance were 90 ml/min at randomization, 125 ml/min on felodipine, 108 ml/min on enalapril and 120 ml/min on the combination. Felodipine and enalapril in low doses are effective antihypertensive agents in elderly people. Felodipine monotherapy is more effective than enalapril monotherapy but a greater blood pressure lowering effect can be obtained with the combination of low doses of enalapril and felodipine. This has the advantage that the number of side effects is less.