Nifedipine and prazosin in the management of pulmonary hypertension in CREST syndrome.

A 62-year-old woman with CREST syndrome and isolated pulmonary hypertension (without evidence of interstitial lung disease) underwent right heart catheterization to evaluate the effect of steroid and vasodilator treatment on hemodynamic parameters. During 12 weeks of prednisone treatment in a dosage of 40 mg daily, her condition markedly deteriorated clinically and hemodynamically as manifested by pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR), cardiac output (CO), mixed venous O2 saturation, and systemic vascular resistance (SVR). Successive trials with various vasodilators demonstrated ineffectiveness of isosorbide dinitrate and phenoxybenzamine, whereas nifedipine was effective in a 15-mg single dose, and prazosin 1 mg was partially effective in reducing PVR, SVR, and increasing CO and mixed venous O2 saturation. The combination of nifedipine 10 mg and prazosin 0.5 mg given alternately every four hours for 48 hours was the most effective in reducing PVR and PAP. Clinical response was favorable as well until treatment with medications was discontinued due to gastrointestinal side effects one month later.