Effectiveness and Safety of New Oxycodone/Acetaminophen Formulations With Reduced Acetaminophen for the Treatment of Low Back Pain

OBJECTIVE. To evaluate the analgesic effectiveness/safety of the new oxycodone 7.5‐ and 10‐mg/acetaminophen 325‐mg (Percocet®) formulations in patients with low back pain (LBP) suboptimally responsive to nonsteroidal anti‐inflammatory drugs, muscle relaxants, tramadol, cyclo‐oxygenase‐2 inhibitors, and/or prn opioids. DESIGN. Prospective, open‐label, nonrandomized, 4‐week trial. SETTING. Multicenter. PATIENTS. Thirty‐three men and women (mean age: 52.2 years) with LBP (mean duration: 10.9 years). INTERVENTIONS. All prior analgesics were discontinued, and oxycodone/acetaminophen was dosed three times a day (TID), titrated to clinically meaningful pain relief. Initial oxycodone/acetaminophen dose: 2.5/325 mg TID; maximum: 20/650 mg TID. Outcome Measures: Effectiveness: Brief Pain Inventory (BPI) and Neuropathic Pain Scale 4 score (sharp, hot, dull, and deep pain). Quality of life: BPI and North American Spine Society Lumbar Spine questionnaire. Safety: Adverse events, physical/neurologic examinations, vital signs, and clinical laboratory tests. RESULTS. In all, 28 of 33 patients (85%) completed the study; discontinuations were for adverse events (N=3), patient choice (N=1), and lack of effectiveness (N =1). The mean oxycodone/acetaminophen dose at the end of treatment was 8.2/325 mg TID. After 4 weeks, treatment significantly reduced BPI pain intensity and improved pain relief ( P < 0.0005), improved Neuropathic Pain Scale 4 score ( P =0.007), reduced pain interference with quality of life ( P < 0.0004), and reduced disability ( P < 0.0001). Treatment was found to be safe and well tolerated. Adverse events were those most commonly expected from an opioid, and most were of mild‐to‐moderate intensity. CONCLUSIONS. The primary purpose of this study was to preliminarily test the effectiveness of the new formulations of oxycodone/acetaminophen with reduced acetaminophen in the clinical practice setting. The results from this trial suggest that these formulations are effective in the treatment of moderate‐to‐severe chronic LBP. Most patients (67%) reported significant pain relief/tolerable side effects with a TID dosing frequency or less (mean: 3.04 doses/day), suggesting chronic pain patients can experience meaningful pain relief with around‐the‐clock dosing of oxycodone/acetaminophen and minimal risk of hepatotoxicity. Further long‐term, controlled studies of the efficacy/safety of the new formulations of oxycodone/acetaminophen in LBP are warranted to fully characterize efficacy in this patient population and corroborate the findings from our study.