• Dose of sustained-release hydromorphone that provides a level of pain control that is equal to the pain control provided by oxycodone (equi-analgesic dosage). [ Time Frame: 24 weeks; visit 8 ] [ Designated as safety issue: No ]
  

• Patient assessment of pain severity on a 10 point scale; the use of add-on medication (for excessive pain); Brief Pain Inventory (a questionnaire for the patient to acess the severity of their pain and impact experienced); and other questionnaires. [ Time Frame: at visit 8 at week 24 and at visit 10 at week 52. ] [ Designated as safety issue: No ]
  

Conventional immediate-release forms of hydromorphone and oxycodone have a relatively short duration of action that require dosing every 4 to 6 hours. To counterbalance the drawback of repeated opioid intake, sustained-release formulations of oxycodone and hydromorphone were developed that allow twice-daily dosing. Subsequently, a novel, once-daily, extended-release hydromorphone formulation was developed to further enhance ease of treatment and improve effectiveness in the treatment of severe pain. This is a randomized, open-label, comparative, parallel-group, 24-week flexible-dose study in patients with chronic noncancer pain severe enough to require continuous opioid therapy. Patients will receive either 8 mg of sustained-release hydromorphone, taken once daily or 10 mg of controlled-release oxycodone, taken twice daily. Individual adjustments in dosing will be performed to achieve satisfactory pain control, up to a maximum daily dosage of 32 mg for hydromorphone and 80 mg for oxycodone. The primary efficacy outcome will be the determination of the dose of hydromorphone that produces a level of pain control that is equal to the pain control provided by oxycodone (equi-analgesic dose). Safety will be monitored throughout the study. The study hypothesis is that sustained-release hydromorphone taken once daily is well tolerated and is not inferior with regard to pain control to controlled-release oxycodone taken twice daily.

Amendment:

Amendment was made to the duration of the study from duration of '24 weeks' to '52 weeks' in order to collect long-term safety and efficacy data. OROS hydromorphone 8, 16, or 32 mg tablets QD or SR oxycodone 10, 20, or 40 mg tablets BID. Individual adjustments in dosing performed to achieve satisfactory pain control over 24 weeks. Amendment: treatment duration was extended to 52 weeks.