NT is taking two Percocet tablets each containing 7.5 mg of Oxycodone and 325 mg of APAP Q4H to manage his pain. His physician wants to switch him to Oxymorphone ER tablets to improve pain control. Oxymorphone ER tabs are available in: 5, 7.5, 10, 15, 20, 30 and 40 mg tablets given Q12H. What would be the most appropriate dose and dosage regimen for this patient? __