A Study to Assess the Efficacy and Safety of 20, 40, and 80mg of Sildenafil Three Times a Day in the Treatment of Pulmonary Arterial Hypertension
A Study to Assess the Efficacy and Safety of 20, 40, and 80mg of Sildenafil Three Times a Day in the Treatment of Pulmonary Arterial Hypertension
To evaluate the effect of three doses of oral sildenafil (20, 40 and 80 mg three times a day
 [TID]) on exercise capacity, as measured by the 6-Minute Walk test, as well as the safety and
 tolerability, after 12 weeks of treatment in subjects with pulmonary arterial hypertension
 who are aged 18 years and over. To investigate the plasma concentration-effect relationship
 and to determine the population pharmacokinetic (PK) parameters.
Inclusion Criteria:

 Included patients had primary pulmonary arterial hypertension, pulmonary hypertension
 secondary to connective tissue disease, or pulmonary hypertension with surgical repair at
 least 5 years previously; a mean pulmonary artery pressure greater than or equal to 25 mmHg
 and a pulmonary artery wedge pressure of less than or equal to 15 mmHg at rest, via right
 heart catheterisation within 21 days prior to randomisation; and a baseline 6-Minute Walk
 test distance of 100 m to 450 m.

 Exclusion Criteria:

 Subjects with congenital heart disease, pulmonary hypertension due to thromboembolism, HIV,
 chronic obstructive airway disease, congestive heart failure or schistosomiasis; subjects
 with significant (ie > 2+) valvular disease other than tricuspid regurgitation or pulmonary
 regurgitation; and acutely decompensated heart failure within the previous 30 days;
 subjects with pulmonary hypertension secondary to any other etiology other than those
 specified in the inclusion criteria.