title: Analgesic effect of intravenous ATP on postherpetic neuralgia in comparison with responses to intravenous ketamine and lidocaine.
abstract: OBJECTIVE
  No study has been performed on the analgesic effect of adenosine 5'-triphosphate (ATP) on postherpetic neuralgia (PHN). We conducted an open-label trial of ATP in patients with PHN, and compared ATP with ketamine and lidocaine.
  
  
  METHODS
  Twelve patients with PHN were studied. On separate days, ketamine (0.3 mg.kg(-1)), lidocaine (2 mg.kg(-1)), and ATP (100 microg.kg(-1).min(-1) or less for 120 min) were administrated intravenously. The intensity of spontaneous pain as well as tactile allodynia was assessed using a visual analog scale (VAS). When the VAS score for spontaneous pain was decreased by more than 50%, the patient was classified as a responder.
  
  
  RESULTS
  Five, 6, and 6 patients responded to ketamine, lidocaine, and ATP, respectively. In 6 ATP responders, pain relief developed slowly and lasted for 9 (median) h (range: 3-72 h). All 5 ketamine responders and only 1 of 7 ketamine nonresponders responded to ATP (5/5 vs 1/7, P < 0.05, chi2 test) whereas 2 of 6 responders to lidocaine and 4 of 6 nonresponders to lidocaine responded to ATP (2/6 vs 4/6, P > 0.05). The ketamine responders responded to ATP more often than did the lidocaine responders (5/5 vs 2/6, P < 0.05).
  
  
  CONCLUSIONS
  Intravenous ATP exerted slowly developing and long-lasting analgesic effects in half of patients with PHN. Patients with ketamine-responsive PHN were likely to respond to ATP.
authors.affiliation: Surgical Center Research Hospital, Institute of Medical Institute, The University of Tokyo, 4-6-1 Shiroganedai, Minato-ku, Tokyo, 108-8639, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Hayashida
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Fukuda
authors.forename: Atsuo
authors.initials: A
authors.lastname: Fukunaga
authors.forename: Aki
authors.initials: A
authors.lastname: Meno
authors.forename: Kanako
authors.initials: K
authors.lastname: Sato
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tarui
authors.forename: Hideko
authors.initials: H
authors.lastname: Arita
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Kazuo
authors.initials: K
authors.lastname: Hanaoka
mesh_terms: D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000700:Analgesics; D000778:Anesthetics, Dissociative / Q000008:administration & dosage / Q000627:therapeutic use*; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006566:Herpesviridae Infections / Q000150:complications*; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage / Q000627:therapeutic use*; D008012:Lidocaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement; D010148:Intractable Pain / Q000188:drug therapy*; D010812:Physical Stimulation
chemical_list: D000700:Analgesics; D000778:Anesthetics, Dissociative; D000779:Anesthetics, Local; D007649:Ketamine; D000255:Adenosine Triphosphate; D008012:Lidocaine