Composite measure to assess efficacy/gastrointestinal tolerability of tapentadol ER versus oxycodone CR for chronic pain: pooled analysis of randomized studies

Objective: To evaluate a composite measure for chronic pain that balances pain relief with tolerability. Design: Post hoc meta-analysis of three randomized, multicenter, double-blind studies. Participants: Subjects with moderate-to-severe chronic osteoarthritis knee pain or low back pain who had been randomized to receive active treatment with tapentadol extended release (ER; n = 978) or oxycodone controlled release (CR; n = 999). Twenty-two subjects were excluded, mainly because they did not receive treatment. Main outcome measures: We defined the composite measure as GTE 30 percent pain relief without nausea/vomiting/constipation and without discontinuations (GTE 30 percent PRT [pain relief/tolerability]). We also considered GTE 50 percent PRT as well as GTE 30 percent and GTE 50 percent pain relief without any adverse events of any type. To further evaluate GTE 30 percent PRT, we studied its relationship with four patient-reported outcomes: EQ-5D, Physical and Mental Component Summaries of SF-36, Patient Global Impression of Change, and Patient Assessment of Constipation Symptoms. Results: At week 12, tapentadol ER recipients were more likely to have GTE 30 percent PRT than oxycodone CR recipients (OR, 3.15; 95% CI, 2.47, 4.00; p < 0.001). Significant differences were also observed with the other three composite measures (p < 0.001). At week 12, subjects with GTE 30 percent PRT had more favorable changes in all patient-reported outcomes than those without and were more likely to have threshold changes in EQ-5D and SF-36 (all p < 0.001). Conclusions: Tapentadol ER was associated with significantly better composite outcomes than oxycodone CR. Because both pain relief and gastrointestinal tolerability appeared to be related to outcomes, the composite measure may represent a useful tool for comparing opioids that merits further evaluation. Keywords: chronic pain, gastrointestinal tolerability, composite measure, opioid, oxycodone, tapentadol DOI:10.5055/jom.2013.0147