Clinical trials with long-term treatment of pulmonary hypertension due to lung disease.

Many drugs have been tested for the treatment of pulmonary hypertension of different origins, but even the acute effects are controversial and side-effects are frequently important. In a few studies, vasodilators have been used in the long-term treatment of chronic pulmonary hypertension related to chronic lung disease (calcium channel blockers, hydralazine, nitrates); here, also, the results are inconstant and the side-effects are sometimes major. No vasodilator specific for the pulmonary circulation is presently available.