title: Effectiveness and safety of new oxycodone/acetaminophen formulations with reduced acetaminophen for the treatment of low back pain.
abstract: 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.
  
  
  METHODS
  Prospective, open-label, nonrandomized, 4-week trial.
  
  
  METHODS
  Multicenter.
  
  
  METHODS
  Thirty-three men and women (mean age: 52.2 years) with LBP (mean duration: 10.9 years).
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
authors.affiliation: Endo Pharmaceuticals Inc., Chadds Ford, Pennsylvania 19317, USA. Gammaitoni.Arnold@Endo.com
authors.forename: Arnold R
authors.initials: AR
authors.lastname: Gammaitoni
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Galer
authors.forename: Peter
authors.initials: P
authors.lastname: Lacouture
authors.forename: John
authors.initials: J
authors.lastname: Domingos
authors.forename: Thomas
authors.initials: T
authors.lastname: Schlagheck
mesh_terms: D000082:Acetaminophen / Q000627:therapeutic use*; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010098:Oxycodone / Q000627:therapeutic use*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D000082:Acetaminophen; D010098:Oxycodone