5. SP is a 50 year old woman with chronic low back pain. She is taking oxymorphone ER 40mg PO BID

5. SP is a 50 year old woman with chronic low back pain. She is taking oxymorphone ER 40mg PO BID. She still reports a pain score of 4/10, down from her baseline of 9/10 but up from last month, which was a 2/10. Your supervising physician decides to start an opioid rotation to attempt to improve analgesic efficacy and would like to switch the patient to methadone with an IR morphine breakthrough regimen. What regimens (including dose, route, and frequency) should you prescribe?