title: Acquired pharmaco-dynamic opioid tolerance: a concept analysis.
abstract: OBJECTIVE
  To report an analysis of the concept of acquired pharmaco-dynamic opioid tolerance.
  
  
  BACKGROUND
  Acquired pharmaco-dynamic opioid tolerance is a complex and poorly understood phenomenon associated with strong opioid therapy for managing pain. Critical review of the concept provides greater clarification of the attributes, assisting healthcare professionals in addressing pain and functional management of patients, particularly those with non-malignant pain.
  
  
  METHODS
  Concept analysis.
  
  
  METHODS
  A systematic literature search was undertaken using electronic data bases: CINAHL, British Nursing Index, EMBase, Medline, Pubmed and AMED. All literature reviewed was in English and published between 1976 and 2012. The key search terms were 'chronic non-malignant pain', 'strong opioid therapy' and 'development of acquired pharmaco-dynamic opioid tolerance'; all possible variant terms were also searched.
  
  
  METHODS
  The Walker and Avant approach was used to guide the concept analysis.
  
  
  RESULTS
  The concept analysis revealed four empirical referents: plasticity, drug administration, reduced analgesic efficacy and increased drug dosing. Tachyphylexia was identified as a borderline case, opioid induced hyperalgesia as a related case and pseudo-tolerance as a contrary case. The antecedent is administration of an opioid analgesic drug and the consequences, increasing opioid drug dose to maintain analgesic effect.
  
  
  CONCLUSIONS
  Untangling the antecedents, empirical referents and consequences of tolerance help healthcare professionals understand its complexities. Improved knowledge may ultimately influence patient outcomes through the construction of better monitoring systems. This concept analysis may also provide insights for policy change and give empirical direction for future research.
authors.affiliation: Anaesthetic Department, Royal Gwent Hospital, Newport, UK.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Middleton
authors.forename: Jane
authors.initials: J
authors.lastname: Harden
mesh_terms: D015746:Abdominal Pain / Q000188:drug therapy / Q000209:etiology; D000222:Adaptation, Physiological / Q000187:drug effects; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D001416:Back Pain / Q000188:drug therapy / Q000209:etiology; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance / Q000502:physiology*; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000139:chemically induced / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy* / Q000503:physiopathology; D013618:Tachyphylaxis / Q000502:physiology
chemical_list: D000701:Analgesics, Opioid
keywords: analysis; chronic; concept; conditions; management; nursing; opioid; tolerance