Opana ER is an extended-release opioid medication used in the management of severe pain. Its active ingredient, oxymorphone, works by binding to specific receptors in the brain and spinal cord to reduce the perception of pain. Due to its potency, Opana ER is commonly prescribed for chronic pain relief when around-the-clock treatment is necessary. It is crucial to follow the prescribed dosage and schedule carefully to prevent the risk of addiction, misuse, or overdose associated with opioid medications.