Effect of benazepril amlodipine combination on fibrinolysis in hypertensive diabetic patients

Objective: The aim of this study was to compare the effects of benazepril and amlodipine in monotherapy versus in combination with plasma t-PA and PAI-1 activity in hypertensive type-2 diabetic patients. Methods: After an initial 6-week wash-out, single-blind placebo period, 38 patients, 17 men and 21 females, were randomly assigned to receive benazepril 10 mg o.d. or amlodipine 5 mg o.d. or their combination o.d. at the same dosage for 6 weeks in three crossover periods each separated by a 2-week placebo wash-out period (3x3 latin square). At the end of the placebo run-in period and of each treatment period, BP, plasma PAI-1 and tPA activity were evaluated. Results: Both benazepril and amlodipine were similarly effective in reducing systolic blood pressure (SBP) (-17.6 mmHg with benazepril and -19.8 mmHg with amlodipine; P <0.001 versus placebo), and diastolic blood pressure (DBP) (-11.1 mmHg, -13.2 mmHg, respectively). Combination therapy produced greater reduction in SBP/DBP values (-28.3/-20.5 mmHg; P <0.001 versus placebo, P <0.01 versus benazepril and amlodipine). Benazepril monotherapy significantly decreased plasma PAI-1 activity (-8.4 IU/ml, P <0.05) while it did not influence t-PA activity (+0.02 IU/ml). Amlodipine monotherapy produced a significant increase in t-PA activity (+ 0.27 IU/ml, P <0.05) while it did not influence PAI-1 activity (+0.8 IU/ml). The amlodipine/benazepril combination produced both a significant decrease in plasma PAI-1 activity (-8.7 IU, P <0.05) and a significant increase in t-PA activity (+ 0.26 IU/ml, P <0.05). Conclusions: These data suggest that in hypertensive type-2 diabetic patients, a population with an impaired fibrinolysis, the benazepril/amlodipine combination, may improve the fibrinolytic balance more than the single drugs.