title: Osteoarthritic pain: a review of current, theoretical and emerging therapeutics.
abstract: BACKGROUND
  Despite exciting progress and growth in the understanding of molecular and cellular mechanisms of chronic pain, osteoarthritis (OA) pain remains a challenging clinical entity to treat. There is an emerging diversity of algogenic mechanisms suggesting heterogeneity in pain aetiology in the OA patient population.
  
  
  OBJECTIVE
  This review article summarises key issues in existing therapies for OA pain and highlights the emerging compounds in early and late development. It also highlights where tolerability may be a concern, especially in the older populations in which treatment interactions for co-morbid conditions may further narrow therapeutic index. Importantly, the authors also examine the diversity of biology that underpins OA pain and highlight the opportunities for the future.
  
  
  CONCLUSIONS
  Many emerging therapies are presently in proof-of-concept clinical testing for treatment of OA. A growing understanding of the heterogeneity in the OA patient population, will challenge the ability to accurately understand observed efficacy or safety signals in these relatively small trials and how they may titrate to a broader patient population. We may need to wait several more years to understand whether the need for a differentiated therapy demanded by patients, payors and physicians alike, will be met.
authors.affiliation: AstraZeneca R&D, Office 12AF1A, Mereside, Alderley Park, Macclesfield, Cheshire, SK10 4TG, UK. Simon.Read@astrazeneca.com
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Read
authors.forename: Andy
authors.initials: A
authors.lastname: Dray
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002186:Cannabinoids / Q000008:administration & dosage / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D005944:Glucosamine / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D007596:Joints / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010003:Osteoarthritis / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D010146:Pain / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism / Q000473:pathology
chemical_list: D000701:Analgesics, Opioid; D000894:Anti-Inflammatory Agents, Non-Steroidal; D002186:Cannabinoids; D005944:Glucosamine