Opana 15mg (Oxymorphone) is a potent opioid analgesic prescribed for individuals suffering from moderate to severe pain. Whether you are dealing with post-surgical pain, chronic conditions, or injury-related discomfort, Opana 15mg provides effective and long-lasting relief. 1.Opana is available in both immediate-release (IR) and extended-release (ER) formulations: Opana IR (Immediate Release) – Works quickly for acute pain episodes. Opana ER (Extended Release) – Provides long-lasting pain relief for chronic pain sufferers.