EFFECTS OF DOXAZOSIN AND ATENOLOL ON THE FIBRINOLYTIC SYSTEM IN PATIENTS WITH HYPERTENSION AND ELEVATED SERUM-CHOLESTEROL

Disturbances in the fibrinolytic system have been associated with cardiovascular disease and its risk factors. In the present study the effects of an alpha-1-adrenoceptor inhibitor (doxazosin) and a selective beta-adrenoceptor blocker (atenolol) on the fibrinolytic system have been evaluated. Eighty four subjects with previously untreated mild to moderate hypertension and elevated serum cholesterol were randomized to receive atenolol or doxazosin in a double-blind study over 6 months. Tissue plasminogen activator(tPA) and plasminogen activator inhibitor (PAI-1) were measured in citrated plasma samples before and after venous occlusion before and at the end of the study period. tPA activity after venous occlusion and tPA capacity were significantly increased after doxazosin as compared to pretreatment values. The fibrinolytic variables did not change in the atenolol group. Thus, doxazosin but not atenolol, improved the activity of the fibrinolytic system in patients with hypertension and an elevated serum cholesterol level. This effect of doxazosin warrants consideration when selecting a first-line antihypertensive drug.