Effect of Benazepril plus Amlodipine vs Benazepril Alone on Urinary Albumin Excretion in Hypertensive Patients with Type II Diabetes and Microalbuminuria

To compare the effect of the combination of benazepril and amlodipine on urinary albumin excretion (UAE) with that of benazepril alone, 45 patients with hypertension and type II (non-insulin-dependent) diabetes mellitus and microalbuminuria were randomised to receive benazepril 10mg plus amlodipine 5mg once daily, or benazepril monotherapy (10mg once daily), for 6 months. Before and after 3 and 6 months of therapy, sitting blood pressure and heart rate, bodyweight, UAE, plasma creatinine and creatinine clearance, glycosylated haemoglobin and plasma levels of glucose, electrolytes, uric acid and nitrogen were evaluated. Both benazepril alone and benazepril plus amlodipine significantly reduced blood pressure values without affecting heart rate and glucose homeostasis, but combination therapy was more effective in lowering both systolic and diastolic blood pressure. At 3 months, there was a similar reduction in UAE in the patients treated with benazepril alone and in those treated with benazepril plus amlodipine, but at 6 months UAE tended to show a greater decrease with the combination (−24.6%, p < 0.02) than with monotherapy (−19.7%, p < 0.04). Creatinine clearance significantly increased during combination therapy (p < 0.02), but was unchanged during benazepril monotherapy.