[Effects of nifedipine on pulmonary hypertension in patients with chronic obstructive pulmonary diseases--a comparison with oxygen administration].

We evaluated the effects of the calcium channel blocker nifedipine (Nf) as a vasodilator compared with oxygen administration on pulmonary hypertension and right ventricular performance in 15 patients with COPD. 1. Compared with baseline, sublingual administration of Nf (average dose 39.3mg) decreased mean pulmonary artery pressure (mPAP) and total pulmonary vascular resistance (TPVR) significantly. Cardiac index (CI) and oxygen transport were increased. PaO2 were unchanged and PvO2 were slightly increased after administration of Nf. 2. Compared with oxygen administration, Nf caused significant fall of TPVR. CI and oxygen transport increased. 3. In eleven of 15 patients, continued hourly Nf doses (from 20 to 60mg) produced a significant reduction in mPAP and TPVR. All patients but one did not produce symptomatic systemic hypotension. We considered that higher dose (30mg) of Nf was required to produce marked hemodynamic response in patients with COPD without any side effect.