Pfizer says it has launched its drug Revatio (sildenafil citrate) as a new treatment for pulmonary arterial hypertension, in the UK.

The drug contains the same active ingredient as Pfizer's blockbuster erectile dysfunction agent Viagra.

In patients with PAH, the pressure in the pulmonary artery increases, causing debilitating symptoms, such as breathlessness, dizziness, fainting, chest pains and tiredness. If left untreated, PAH patients have an average survival time of less than three years from diagnosis. Revatio has been shown to reduce pulmonary artery pressure and improve exercise capacity.

Pfizer's drug became the first oral treatment for PAH to be approved in the European Union for patients with an early stage of the disease last November, and will muscle in on a number of other drugs approved to treat PAH in recent years, including Swiss company Actelion Pharmaceuticals' endothelin antagonist Tracleer (bosentan), currently its leading product , and CoTherix' Ventavis (iloprost). Revatio was cleared in the USA in June 2005

In the UK, the price of Revatio is £373.50 for a pack of 90 tablets (30 days’ supply), according to a report on the National Health Service’s National Electronic Library of Medicines website. The approved dose is 20mg three times a day.