Objective: Tapentadol is a new, centrally acting analgesic with two mechanisms of action, combining μ-opioid agonism and norepinephrine reuptake inhibition in a single molecule. This study assessed tapentadol immediate release (IR) in patients with postsurgical orthopedic pain.
Methods: This randomized, double-blind, phase II study involved patients with moderate-to-severe pain after bunionectomy surgery (first metatarsal with osteotomy). Patients (N = 269) were randomly assigned to receive tapentadol IR 50 or 100 mg, oxycodone HCl IR 10 mg, or placebo; the study drug was taken every 4-6 h, over a 72-h period starting 1 day after surgery (Evaluation Day 2). The primary endpoint was the sum of pain intensity over 24 h (SPI-24) on the second day after randomization (Evaluation Day 3). Potential limitations of this study included the use of rescue medication and the fact that it was not powered to statistically compare between-group differences in tolerability measures.
Results: Mean (standard deviation [SD]) SPI-24 values on Evaluation Day 3 were significantly lower for tapentadol IR (50 mg: 33.6 [19.7], p = 0.0133; 100 mg: 29.2 [15.2], p = 0.0001) and oxycodone HCl IR 10 mg (35.7 [17.2]; nominal p = 0.0365) compared with placebo (41.9 [17.7]). The most common treatment-emergent adverse events for all treatment groups were characteristic of drugs with μ-opioid agonist activity. While providing similar analgesic efficacy, tapentadol IR 50 mg was associated with lower rates of nausea (46.3% vs. 71.6% for oxycodone HCl IR 10 mg), dizziness (32.8% vs. 56.7%), vomiting (16.4% vs. 38.8%), and constipation (6.0% vs. 17.9%), and a similar rate of somnolence (28.4% vs. 26.9%) compared with oxycodone HCl IR 10 mg.
Conclusions: Tapentadol IR 50 and 100 mg and oxycodone HCl IR 10 mg were effective in this study for the relief of acute postoperative pain following bunionectomy. The study results suggest improved gastrointestinal tolerability of tapentadol IR 50 mg compared with oxycodone at a dose showing comparable efficacy.