The patent on Revatio indicated for pulmonary arterial hypertension rather than erectile dysfunction expired in late It is thought that this reduced sales over the Internet and was safer as males could be referred for medical advice if appropriate. This, in my view, is the key issue in this appeal. History Sildenafil compound UK, was synthesized by a group of pharmaceutical chemists led by Simon Campbell [55] working at Pfizer’s Sandwich, Kent , research facility in England. The Korean Court system made a ruling against Pfizer in June , allowing for the unhindered domestic production of generic prescription sildenafil.Kamagra mg Tablet is a prescription medicine used to treat erectile dysfunction (impotence) in men. It works by increasing blood flow to the penis. This helps men to get or maintain an erection. It belongs to a group of medicines known as phosphodiesterase type 5 (PDE 5) inhibitors.  · Buy Kamagra mg online – USA/UK and World. Home. eLearning Authors. Yvonne Ho. Sildenafil milligram tablets (prescription in the European Union) Pfizer’s patent on sildenafil citrate expired in some member countries of the EU, Austria, Denmark, France, Germany, Ireland, Italy, The Netherlands, Spain, Sweden, the United Kingdom and Switzerland on 21 June