FELODIPINE IMPROVES PULMONARY HEMODYNAMICS IN CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Pulmonary hypertension in chronic obstructive pulmonary disease (COPD) is associated with a poor prognosis. Reduction of pulmonary artery pr essure in COPD by prolonged oxygen treatment has been shown to be asso ciated with increased survival. In an attempt to find a suitable pharm acologic method of reducing pulmonary artery pressure and pulmonary va scular resistance in COPD, we enrolled 13 stable pulmonary-hypertensiv e, hypoxemic COPD patients in a study to test the effects of felodipin e, a relatively new, vascular-selective calcium antagonist. Doppler ec hocardiography was used to estimate pulmonary artery pressure and card iac output before treatment, 2, 7, and 12 weeks during felodipine trea tment (10 to 20 mg/d), and after a 1-week placebo washout period. Meas urements of lung function, arterial blood gases, and exercise capacity during an incremental bicycle ergometer test were also performed at i ntervals during the study period. Three patients withdrew from the stu dy and of the remaining 10, 8 had some side effects of medication (per ipheral edema or headache) that improved either spontaneously or follo wing a reduction in drug dose. In the 10 patients who completed the st udy (8 male; mean age, 67 years), felodipine resulted in significant r eductions in mean pulmonary artery pressure (22 percent) and total pul monary (vascular) resistance (30 percent) and increases in cardiac out put (15 percent) and stroke volume (13 percent) compared with baseline measurements and those taken after placebo washout. These effects wer e sustained over the 12 weeks of felodipine treatment. There was no ad verse effect of felodipine treatment on pulmonary gas exchange at rest or during exercise and no change in lung function or exercise capacit y. We conclude that in pulmonary hypertensive, hypoxemic COPD patients , felodipine substantially improves pulmonary hemodynamics.