An Open-Label Safety and Tolerability Study of Immediate-Release and Extended-Release Oxymorphone in Opioid-Tolerant Pediatric Subjects With Chronic Pain.

Patients will convert from current opioid to Oxymorphone ER and undergo titration. During the Titration Period, subjects will receive daily oxymorphone Extended Release tablets(s) every 12 hours. Dosing adjustments will be based on the review of the subject's pain scores. Oxymorphone IR 5 mg will be provided to be used as supplemental "breakthrough" pain medication (as needed). Titration Period will end when the fixed dose of study medication is tolerated and the subject achieves adequate analgesia. Subjects will then proceed to the open-label 3-month maintenance period on the fixed dose of study medication established during the Titration Period.