Long-term treatment with a new calcium antagonist, felodipine, in chronic obstructive lung disease.

Nine patients with advanced chronic obstructive lung disease (COLD) were treated with a calcium antagonist, felodipine, for 3-5 months and their central haemodynamics and pulmonary gas exchange were then studied. The systemic vascular resistance was reduced by 19% (p less than 0.05) at rest and by 30% during ergometer bicycle exercise (p = 0.05) compared to pretreatment data, whereas pulmonary vascular resistance showed a borderline reduction of 10% at rest and 30% during exercise (p = 0.12 and p = 0.10, respectively). Stroke volume increased by 13% (p less than 0.05) at rest and to the same extent at exercise. A moderate deterioration of the ventilation-perfusion relationship was seen by the multiple inert gas elimination technique, and the arterial oxygen tension was further reduced by 3.5 mmHg (p less than 0.05) at rest and by 3.0 mmHg on exercise, but the working capacity on an ergometer bicycle increased from 60 to 70 W (p less than 0.01). No acceptable predictor of patients who would respond to the drug could be found.