Tapentadol Extended Release Associated with Lower Rates, Longer Times to Discontinuation Due to Gastrointestinal Adverse Events than Oxycodone Controlled-Release

BALTIMORE, Md.—Prior opioid experience had no effect on discontinuation of tapentadol extended-release (ER) due to gastrointestinal treatment-emergent adverse events (TEAEs) in patients with moderate-to-severe chronic low back or osteoarthritis pain, investigators reported during the American Pain Society’s 29th Annual Scientific Meeting. In addition, patients receiving tapentadol ER, an investigational therapy, had lower rates and longer times to discontinuation compared with those receiving oxycodone controlled release (CR).

Results of a phase III randomized, open-label, one-year safety study, in which tapentadol ER 100 to 250 mg bid (n=894) demonstrated similar pain relief to oxycodone HCl CR 20 to 50 mg bid (n=223), were evaluated in a post-hoc analysis to determine discontinuations for any TEAE and due to constipation, nausea, or vomiting. Study patients were stratified by whether they had prior opioid experience, defined as use of opioid medications within 3 months of screening. Kaplan-Meier methods (treatment differences compared by the log-rank test) estimated distributions of times to first onset and discontinuation due to constipation, nausea, and vomiting, and discontinuation rates were evaluated with Fisher’s exact test.

Of 1117 patients in the study, 532 were opioid-naïve (421 in the tapentadol ER group and 111 in the oxycodone CR group), and 585 were opioid-experienced (473 in the tapentadol ER group and 112 in the oxycodone CR group). Opioid-naïve patients receiving tapentadol ER discontinued for any TEAE and gastrointestinal TEAEs at a significantly lower rate than those in the oxycodone CR group, 25.2% vs 53.2% and 10.2% vs 30.6%, respectively (both P<0.0001), David M. Biondi, DO, of Ortho-McNeil Janssen Scientific Affairs, Raritan, NJ, and colleagues reported. This difference was not observed among opioid-experienced patients: 19.5% of those receiving tapentadol ER and 20.5% receiving oxycodone CR discontinued for any TEAE (P=0.792) and 7.2% and 12.5%, respectively, discontinued for gastrointestinal TEAEs (P=0.083).

Times to first onset of constipation, nausea, and vomiting occurred significantly later with tapentadol ER compared with oxycodone CR among the opioid-naïve patients (all P≤0.0001). Among opioid-experienced patients, times to first onset of constipation and nausea occurred significantly later with tapentadol ER vs oxycodone CR (P≤0.0001 and P=0.042, respectively); results were not significant for vomiting (P=0.188).

Opioid-naïve patients discontinued treatment with tapentadol ER significantly later due to constipation, nausea, or vomiting (all P≤0.0001) compared with oxycodone CR. Opioid-experienced patients also discontinued treatment with tapentadol ER significantly later due to constipation (P=0.0107) and nausea (P=0.0025) compared with oxycodone CR. Results were not significant for vomiting.