Oxycodone 40mg, a strong prescription opioid medication, is used for moderate to severe pain due to a diagnosis that is not manageable by other treatments. Oxy 40mg is in the class of drugs called narcotic analgesics and is available in both IR or immediate release, as well as ER or extended release forms. The OP 40 pill is considered a high dose of Oxycodone that is usually used to treat patients