Generic Viagra copy "Nurigra" is seen in this photo illustration at a drugstore in Seoul June 2, 2012. South Korean pharmaceutical firms are rushing out generic Viagra copies with names like "Nurigra" and "Happigra" to tap into the erectile dysfunction drug market now that a court has ruled in their favour. Pfizer's patent on Viagra active ingredient sildenafil expired on May 17, since when six local companies, including CJ Cheiljedang and Hanmi Pharm, have released prescription-only generic versions. REUTERS/Lee Jae-Won (SOUTH KOREA - Tags: BUSINESS HEALTH)