Conditions: Pulmonary Arterial Hypertension
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 105
Healthy volunteers: no

Brief summary:
To assess the efficacy and safety of sildenafil when added to patients with PAH who are taking bosentan as all or part of their background therapy.

Detailed description:

Arms:
arm 1: None arm 2: None

Interventions: intervention 1: Bosentan intervention 2: Placebo intervention 3: Bosentan intervention 4: Sildenafil Citrate
Intervention descriptions: intervention 1: Bosentan + Placebo for 12 weeks of the study (double blind), then 12 months open label phase (bosentan + sildenafil) intervention 2: Bosentan + Placebo for 12 weeks of the study (double blind), then 12 months open label phase (bosentan + sildenafil) intervention 3: Bosentan + Sildenafil for 12 weeks of the study (double blind), then 12 months open label phase intervention 4: Bosentan + Sildenafil for 12 weeks of the study (double blind), then 12 months open label phase

Protocol document: