title: Adjuvant topical therapy with a cannabinoid receptor agonist in facial postherpetic neuralgia.
abstract: BACKGROUND
  Postherpetic neuralgia is a frequent adverse event in herpes zoster patients and difficult to treat. Conventional analgetic therapy often fails to reduce the burning pain transmitted by unmyelinated nerve fibers. These nerves express cannabinoid receptors which exert a role in modulation of nociceptive symptoms. Therefore, topical therapy with cannabinoid receptor agonist seems likely to suppress local burning pain.
  
  
  METHODS
  In an open-labeled trial, 8 patients with facial postherpetic neuralgia received a cream containing the cannabinoid receptor agonist N-palmitoylethanolamine. The course of symptoms was scored with the visual analog scale.
  
  
  RESULTS
  5 of 8 patients (62.5 %) experienced a mean pain reduction of 87.8 %. Therapy was tolerated by all patients. No unpleasant sensations or adverse events occurred.
  
  
  CONCLUSIONS
  Topical cannabinoid receptor agonists are an effective and well-tolerated adjuvant therapy option in postherpetic neuralgia.
authors.affiliation: Competence Center for the Diagnosis and Treatment of Pruritus, Clinic and Polyclinic for Skin Diseases, University Hospital of Münster, Germany. sonja.staender@uni-muenster.de
authors.forename: Ngoc Quan
authors.initials: NQ
authors.lastname: Phan
authors.forename: Dorothee
authors.initials: D
authors.lastname: Siepmann
authors.forename: Ingrid
authors.initials: I
authors.lastname: Gralow
authors.forename: Sonja
authors.initials: S
authors.lastname: Ständer
mesh_terms: D000287:Administration, Topical; D000368:Aged; D000369:Aged, 80 and over; D000577:Amides; D000700:Analgesics / Q000008:administration & dosage*; D063386:Cannabinoid Receptor Agonists; D063388:Endocannabinoids; D004983:Ethanolamines; D005145:Face / Q000294:innervation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D051474:Neuralgia, Postherpetic / Q000188:drug therapy*; D009619:Nociceptors / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D010169:Palmitic Acids / Q000008:administration & dosage*
chemical_list: D000577:Amides; D000700:Analgesics; D063386:Cannabinoid Receptor Agonists; D063388:Endocannabinoids; D004983:Ethanolamines; D010169:Palmitic Acids; C005958:palmidrol