Opana ER is the brand name medication for the generic drug named Oxymorphone. ER is the extended-release formulation of the Opana drug. This medicine is used in the treatment of patients suffering from different kinds of pain whether it is moderate or severe. This drug is used for a particular type of treatment of pain which is known as around-the-clock treatment. You can now buy Opana ER onlineOpana ER belongs to the class of medications called by the name opioid analgesics. This medication is considered a long-acting opioid analgesic. Oxymorphone along with the generic medication is also an essential ingredient of Opana ER. This drug comes in a category of Schedule Class II (CII) medications.