Abstract
BACKGROUND: Long-acting opioid formulations are advocated for maintaining pain control in chronic cancer pain. OROS(R) hydromorphone is a sustained-release formulation of hydromorphone that requires dosing once daily to maintain therapeutic concentrations. The objective of this study was to demonstrate the clinical equivalence of immediate-release and sustained-release formulations of hydromorphone and morphine for chronic cancer pain. METHODS: 200 patients with cancer pain (requiring 70% of investigators and patients rated both treatments as good to excellent. The safety profiles of hydromorphone and morphine were similar and typical of opioid analgesics. CONCLUSION: Equivalence was demonstrated for immediate-release formulations of hydromorphone and morphine, but not for the sustained-release formulations of OROS(R) hydromorphone and controlled-release morphine. The direction of the mean difference between the treatments (-0.8) and the out-of-range lower limit of the 95% CI (-1.6) were in favor of OROS(R) hydromorphone. TRIAL REGISTRATION: ClinicalTrials.gov: NCT0041054.