Sildenafil for primary pulmonary hypertension: short and long-term symptomatic benefit.

We report two cases of primary pulmonary hypertension (PPH) who benefited from oral sildenafil therapy. Both demonstrated a substantial improvement in exercise ability, which has been sustained at 3 and 6 months. Sildenafil acting as a phosphodiesterase 5 inhibitor may have an important role to play in the management of PPH and we believe further study to be of importance.