In the UK, with the exception of Nurofen (which is ibuprofen but lots of people use the term for many painkillers as if it's the name of the drug rather than a brand name), we hardly ever use brand names in place of the name of the actual drug. In fact, with the exception of Nurofen, I couldn't tell you the brand name of any painkiller. The most common painkillers are just referred to as paracetamol, ibuprofen and aspirin.