Doxazosin in the treatment of hypertension in patients with chronic obstructive pulmonary disease

This study evaluated the effects of doxazosin, a new alpha₁-adrenergic inhibitor, on blood pressure and pulmonary volumes and flows in ten patients (eight men and two women; age range, 53 to 66 years) with essential hypertension and concomitant chronic obstructive pulmonary disease (COPD). The single-blind study was conducted for 14 weeks and subdivided into three phases: placebo, titration, and maintenance phases. Patients first received placebo for four weeks, followed by active treatment with doxazosin 1 mg/day; this dose was increased to 2, 4 and 8 mg/day, depending on response. Systolic and diastolic blood pressure were significantly reduced by treatment with doxazosin after 14 weeks in the supine and standing positions. There were no significant changes in heart rate or urinary and plasmatic catecholamines. The ventilatory function parameters showed only a slight (but not statistically significant) improvement compared with the placebo phase. These results indicate that treatment with doxazosin significantly reduced systolic and diastolic blood pressure values without a change in the respiratory function tests, in patients with essential hypertension and concomitant COPD.