Pfizer Inc has submitted regulatory filings in the United States and Europe for Revatio (sildenafil citrate) as a treatment for pulmonary arterial hypertension (PAH), a rare, aggressive and life-shortening vascular disease. Sildenafil is the active ingredient in Viagra, Pfizer's erectile dysfunction medication used by more than 23 million men worldwide.

The company filed a New Drug Application for Revatio with the US FDA and submitted its Revatio dossier to regulatory authorities in the Netherlands and Spain, the rapporteur and co-rapporteur sponsors, and the European Medicines Agency (EMEA).

"The regulatory filings for sildenafil usage in PAH demonstrate Pfizer's commitment to address unmet medical conditions by exploring new uses for our existing medicines, together with our significant efforts to discover and develop new compounds," Joseph Feczko, president of Worldwide Development said adding, "PAH is a condition for which new treatment options are desperately needed."

Clinical studies conducted throughout the world have shown sildenafil 20 mg taken three times daily to be effective in treating PAH. Patients treated with sildenafil had improved physical functioning as demonstrated by increased walking distance over a six-minute time interval. Patients on sildenafil also had both a reduction in blood pressure in arteries of the lungs and an increase in cardiac (heart) output which is critical in treatments of this disease, the company release said.

PAH, often referred to as high blood pressure of the lungs, affects approximately 100,000 people in North America and Europe. Those afflicted are usually women between the ages of 21 and 50.

Revatio will be manufactured and marketed in a different dosage, colour and shape than Viagra.