Opana ER 5 mg is indicated for the relief of moderate-to-severe pain in patients who require around-the-clock pain management for an extended period and belongs to the drug class Opioids (narcotic analgesics). It is a semi-synthetic opioid analgesic supplied and a controlled substance. Oxymorphone is the generic version of Opana ER 5 mg. The light-blue round pill with the imprint “E612 5” on one side has been identified as Opana 5 mg. Endo Pharmaceuticals Inc. supplies it with the National Drug Code (NDC) 35356-0499. There are no disadvantages to using Opana ER 5 mg with the new formulation as compared to the old one. The recommended dose is 5 mg (if needed) every 12 hours per day on an empty stomach at least 1 hour before or 2 hours after eating, based on your medical condition and response to treatment. Some side effects caused by Opana ER 5 mg are backache, joint pain, weakness, abdominal cramps, insomnia, diarrhea, constipation, nausea, vomiting, dizziness, dry mouth, drowsiness, anxiety, headache, etc. It is recommended to keep out of children and pets because this medication can be abused.