Pulmonary Arterial Hypertension Indicated for pulmonary arterial hypertension (PAH, WHO Group I) to delay disease progression and reduce the risk of hospitalization for PAH Starting dose: 200 mcg PO BID Increase dose by increments of 200 mcg BID, usually at weekly intervals, to the highest tolerated dose; not to exceed 1600 mcg BID Hepatic impairment Mild (Child-Pugh A): No dosage adjustment required Moderate (Child-Pugh B): Starting dose is 200 mcg qDay; increase by increments of 200 mcg/day at weekly intervals, as tolerated Severe (Child-Pugh C): Avoid use