title: Intravenous vs subcutaneous naloxone for out-of-hospital management of presumed opioid overdose.
abstract: OBJECTIVE
  To determine whether naloxone administered i.v. to out-of-hospital patients with suspected opioid overdose would have a more rapid therapeutic onset than naloxone given subcutaneously (s.q.).
  
  
  METHODS
  A prospective, sequential, observational cohort study of 196 consecutive patients with suspected opioid overdose was conducted in an urban out-of-hospital setting, comparing time intervals from arrival at the patient's side to development of a respiratory rate > or =10 breaths/min, and durations of bag-valve-mask ventilation. Subjects received either naloxone 0.4 mg i.v. (n = 74) or naloxone 0.8 mg s.q. (n = 122), for respiratory depression of <10 breaths/min.
  
  
  RESULTS
  Mean interval from crew arrival to respiratory rate > or =10 breaths/min was 9.3 +/- 4.2 min for the i.v. group vs 9.6 +/- 4.58 min for the s.q. group (95% CI of the difference -1.55, 1.00). Mean duration of bag-valve-mask ventilation was 8.1 +/- 6.0 min for the i.v. group vs 9.1 +/- 4.8 min for the s.q. group. Cost of materials for administering naloxone 0.4 mg i.v. was $12.30/patient, compared with $10.70/patient for naloxone 0.8 mg s.q.
  
  
  CONCLUSIONS
  There was no clinical difference in the time interval to respiratory rate > or =10 breaths/min between naloxone 0.8 mg s.q. and naloxone 0.4 mg i.v. for the out-of-hospital management of patients with suspected opioid overdose. The slower rate of absorption via the s.q. route was offset by the delay in establishing an i.v.
authors.affiliation: British Columbia Ambulance Service, Vancouver, Canada. karen.wanger@moh.hnet.bc.ca
authors.forename: K
authors.initials: K
authors.lastname: Wanger
authors.forename: L
authors.initials: L
authors.lastname: Brough
authors.forename: I
authors.initials: I
authors.lastname: Macmillan
authors.forename: J
authors.initials: J
authors.lastname: Goulding
authors.forename: I
authors.initials: I
authors.lastname: MacPhail
authors.forename: J M
authors.initials: JM
authors.lastname: Christenson
mesh_terms: D000328:Adult; D015331:Cohort Studies; D062787:Drug Overdose; D004632:Emergency Medical Services / Q000191:economics; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008297:Male; D009270:Naloxone / Q000008:administration & dosage* / Q000627:therapeutic use; D009292:Narcotic Antagonists / Q000008:administration & dosage* / Q000627:therapeutic use; D009293:Opioid-Related Disorders / Q000188:drug therapy* / Q000503:physiopathology; D011446:Prospective Studies; D012119:Respiration; D012151:Resuscitation
chemical_list: D009292:Narcotic Antagonists; D009270:Naloxone