Opana ER 5 mg is an extended-release opioid analgesic used to manage moderate to severe pain in patients who require around-the-clock pain relief. Containing oxymorphone as its active ingredient, Opana ER 5 mg works by altering the way the brain and nervous system respond to pain. Due to its potent nature and risk of addiction, misuse, or overdose, it is essential to take Opana ER exactly as prescribed by a healthcare provider. This medication should not be crushed or chewed to prevent a potentially dangerous release of the drug.