Opana ER (oxymorphone) is an extended-release formulation of the opioid analgesic oxymorphone, used to manage severe pain that requires around-the-clock treatment. It is typically prescribed for individuals who have become tolerant to other opioids and need a stronger pain relief option. Due to its potential for abuse and serious side effects, Opana ER should be used only under the strict supervision of a healthcare provider. Always consult a healthcare professional for specific medical advice and information.