Calcium channel blockers in primary pulmonary hypertension.

The demonstration that the calcium channel blockers reduce pulmonary vasomotor tone in experimental models of pulmonary hypertension has served as the rationale for their use in the management of primary pulmonary hypertension. The three currently available agents, verapamil, nifedipine, and diltiazem, have varying degrees of pulmonary vasoactivity. Experience with their use is reviewed.