Adverse reactions which occurred in > 1% of Revatio-treated patients and were more frequent (> 1% difference) on Revatio in the pivotal study or in the Revatio combined data set of both the placebo- controlled studies in pulmonary arterial hypertension, at doses of 20, 40 or 80 mg three times a day are listed in the table below by class and frequency grouping (very common (≥ 1/ 10), common (≥ 1/ 100, < 1/ 10), uncommon (≥ 1/ 1000, < 1/ 100) and not known (cannot be estimated from the available data).