A COMPARISON OF 2 LONG-ACTING VASOSELECTIVE CALCIUM-ANTAGONISTS IN PULMONARY-HYPERTENSION SECONDARY TO COPD

Study objectives and patients: Pulmonary hypertension (PH) is common i n COPD and may predict mortality in this disorder, We have compared th e pulmonary vasodilator effects, dose-response characteristics, and to lerability of two calcium channel blockers, amlodipine and extended-re lease (ER) felodipine, in 10 patients (seven men, age 68 +/- 4.8 [SD] years) with clinically stable COPD and PH, Design: Drugs were given in equal single daily oral doses (2.5, 5, and 10 mg), increasing weekly for 3 weeks, in a randomized investigator-blinded crossover manner wit h a 1-week wash-out period between the two treatments. Measurements: D oppler measurements of pulmonary hemodynamics were made on the seventh day of treatment at each drug dose, Lung function, arterial blood gas es, and adverse events were also monitored weekly. Results: A dose-dep endent decline of pulmonary artery pressure (PAP) was observed with ea ch drug, A dose of 2.5 mg produced a significant decrease in PAP compa red with baseline (20% amlodipine, 17% felodipine ER). Additional decr eases in PAP were observed at 5 mg and 10 mg that were similar for bot h drugs, but did not reach statistical significance compared with 2.5 mg. There was a dose-related decrease in pulmonary vascular resistance and increase in oxygen delivery with amlodipine and felodipine ER, Lu ng function and blood gas values were stable throughout, Side effects (headache and ankle edema) were less frequent during amlodipine treatm ent (p < 0.05). Conclusions: Both amlodipine and felodipine ER, given as a single daily oral dose of greater than or equal to 2.5 mg, are ef fective pulmonary vasodilators in COPD patients with PH, Their dose-re sponse characteristics are similar, but amlodipine treatment was assoc iated with fewer side effects.