title: Dronabinol and chronic pain: importance of mechanistic considerations.
abstract: BACKGROUND
  Although medicinal cannabis has been used for many centuries, the therapeutic potential of delta-9-tetrahydrocannabinol (Δ9-THC; international non-proprietary name = dronabinol) in current pain management remains unclear. Several pharmaceutical products with defined natural or synthesized Δ9-THC content have been developed, resulting in increasing numbers of clinical trials investigating the analgesic efficacy of dronabinol in various pain conditions. Different underlying pain mechanisms, including sensitization of nociceptive sensory pathways and alterations in cognitive and autonomic processing, might explain the varying analgesic effects of dronabinol in chronic pain states.
  
  
  METHODS
  The pharmacokinetics, pharmacodynamics and mechanisms of action of products with a defined dronabinol content are summarized. Additionally, randomized clinical trials investigating the analgesic efficacy of pharmaceutical cannabis based products are reviewed for the treatment of chronic nonmalignant pain.
  
  
  CONCLUSIONS
  We suggest a mechanism-based approach beyond measurement of subjective pain relief to evaluate the therapeutic potential of dronabinol in chronic pain management. Development of objective mechanistic diagnostic biomarkers reflecting altered sensory and cognitive processing in the brain is essential to evaluate dronabinol induced analgesia, and to permit identification of responders and/or non-responders to dronabinol treatment.
authors.affiliation: Radboud University Medical Center, Department of Surgery, Pain and Nociception Neuroscience Research Group , Route 690, PO Box 9101, 6500 HB Nijmegen , The Netherlands +31 024 361 0903 ; +31 024 354 0501 ; marjan.devries@radboudumc.nl.
authors.forename: Marjan
authors.initials: M
authors.lastname: de Vries
authors.forename: Dagmar C M
authors.initials: DC
authors.lastname: van Rijckevorsel
authors.forename: Oliver H G
authors.initials: OH
authors.lastname: Wilder-Smith
authors.forename: Harry
authors.initials: H
authors.lastname: van Goor
mesh_terms: D018712:Analgesics, Non-Narcotic / Q000493:pharmacokinetics / Q000627:therapeutic use*; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000503:physiopathology; D059350:Chronic Pain / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology; D003071:Cognition / Q000187:drug effects; D013759:Dronabinol / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006801:Humans; D059408:Pain Management
chemical_list: D018712:Analgesics, Non-Narcotic; D013759:Dronabinol
keywords: cannabinoids; chronic pain; delta-9-tetrahydrocannabinol; dronabinol; tetrahydrocannabinol