Effects of isosorbide dinitrate on pulmonary hypertension in chronic obstructive pulmonary disease.

Eighteen patients with chronic obstructive pulmonary disease with pulmonary hypertension were studied to assess the hemodynamic response to acute oxygen administration and to oral isosorbide dinitrate (ISDN). All 18 patients had baseline hemodynamic measurements and hemodynamic measurements during low-flow nasal oxygen. Following a second baseline measurement, patients received either oral ISDN (11 patients) or placebo (7 patients) in a randomized, double-blind protocol. Heart rate decreased with oxygen administration but there were no other significant hemodynamic changes. With oral ISDN, there was a significant fall in pulmonary artery and brachial artery pressure. Cardiac output, right atrial pressure, pulmonary wedge pressure, and pulmonary vascular resistance all fell but not significantly. We conclude that oral ISDN is effective in reducing pulmonary hypertension in patients with chronic obstructive pulmonary disease.