BALTIMORE, Md.—Lower incidences and rates of discontinuation due to gastrointestinal treatment-emergent adverse events (TEAEs) among elderly patients with moderate-to-severe low back or osteoarthritis pain suggest that tapentadol immediate-release (IR) may be a better treatment option than oxycodone IR.

Gary J. Vorsanger, PhD, MD, of Ortho-McNeil Janssen Scientific Affairs, Raritan, N.J., and colleagues conducted a post-hoc analysis of a randomized, double-blind, active-controlled, parallel-group, flexible-dose study which evaluated the safety profile of tapentadol IR 50 mg or 100 mg every 4 to 6 hours. Analyses were performed to evaluate tolerability of tapentadol IR among 158 patients compared with 45 patients who received oxycodone IR. All patients were 65 years of age or older. Kaplan-Meier plots were used to estimate times to onset of constipation, nausea, and vomiting, and percentages of treatment days with these TEAEs were calculated.

Among elderly patients who received tapentadol IR, 77.2% reported TEAEs vs 88.9% who received oxycodone IR; for gastrointestinal TEAEs, incidence was 46.8% and 68.9%, respectively. Incidences of constipation were significantly lower with tapentadol IR vs oxycodone IR (19.0% vs 35.6%), as was the composite of nausea or vomiting (30.4% vs 51.1%; P<0.05). For both nausea and constipation, initial onsets occurred significantly earlier with oxycodone IR vs tapentadol IR (P≤0.0312 and P≤0.0181).

Constipation occurred for a greater percentage of treatment days with oxycodone IR (P=0.0203); during treatment, those receiving oxycodone IR initiated laxatives and/or stool softeners at a higher percentage (22.2%) than patients receiving tapentadol IR (12.0%). Please see corresponding PowerPoint slide for more information. Incidences of study discontinuation due to TEAEs were 31.6% for tapentadol IR and 37.8% oxycodone IR; for GI TEAEs, the patient discontinuation rate was 15.8% for tapentadol IR and 24.4% for oxycodone IR. Please see corresponding PowerPoint slide for more information.

Results of this study were presented during the 29th Annual Scientific Meeting of the American Pain Society.