title: Oxycodone combined with opioid receptor antagonists: efficacy and safety.
abstract: BACKGROUND
  A mu receptor antagonist combined with oxycodone (OXY) may improve pain control, reduce physical tolerance and withdrawal, minimizing opioid-related bowel dysfunction and act as an abuse deterrent.
  
  
  METHODS
  The authors cover the use of OXY plus ultra-low-dose naltrexone for analgesia and the use of sustained-release OXY plus sustained-release naloxone to reduce the opioid bowel syndrome. The authors briefly describe the use of sustained-release OXY and naltrexone pellets as a drug abuse deterrent formulation. Combinations of ultra-low-dose naltrexone plus OXY have been in separate trials involved in patients with chronic pain from osteoarthritis and idiopathic low back pain. High attrition and marginal differences between ultra-low-dose naltrexone plus OXY and OXY led to discontinuation of development. Prolonged-release (PR) naloxone combined with PR OXY demonstrates a consistent reduction in opioid-related bowel dysfunction in multiple randomized controlled trials. However, gastrointestinal side effects, including diarrhea, were increased in several trials with the combination compared with PR OXY alone. Analgesia appeared to be maintained although non-inferiority to PR OXY is not formally established. There were flaws to trial design and safety monitoring. Naltrexone has been combined with OXY in individual pellets encased in a capsule. This combination has been reported in a Phase II trial and is presently undergoing Phase III studies.
  
  
  CONCLUSIONS
  Due to the lack of efficacy the combination of altered low-dose naltrexone with oxycodone should cease in development. The combination of sustained release oxycodone plus naloxone reduces constipation with a consistent benefit. Safety has been suboptimally evaluated which is a concern. Although the drug is commercially available in several countries, ongoing safety monitoring particularly high doses would be important.
authors.affiliation: Taussig Cancer Institute, Cleveland Clinic, Harry R. Horvitz Center for Palliative Medicine, Department of Solid Tumor Oncology, 9500 Euclid Ave, Cleveland, OH 44195, USA. davism6@ccf.org
authors.forename: Mellar
authors.initials: M
authors.lastname: Davis
authors.forename: Harold W
authors.initials: HW
authors.lastname: Goforth
authors.forename: Pam
authors.initials: P
authors.lastname: Gamier
mesh_terms: D000701:Analgesics, Opioid / Q000009:adverse effects* / Q000627:therapeutic use*; D000818:Animals; D017322:Clinical Trials, Phase II as Topic; D017326:Clinical Trials, Phase III as Topic; D004338:Drug Combinations; D006801:Humans; D010098:Oxycodone / Q000009:adverse effects* / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors*
chemical_list: D000701:Analgesics, Opioid; D004338:Drug Combinations; D017450:Receptors, Opioid, mu; D010098:Oxycodone