Subcutaneous prostacyclin (treprostinil) is an effective short-term treatment for pulmonary hypertension. The most frequently described adverse effect-pain in the area of injection-rarely requires that treatment be withdrawn. Sildenafil is a selective fosfodiesterase-5 inhibitor with pulmonary vasodilating effects. We describe the use of sildenafil as a substitute for treprostinil in a patient with pulmonary hypertension associated with lupus erythematosus. Treatment with treprostinil was discontinued due to uncontrollable abdominal pain.