title: Onset of acetaminophen analgesia: comparison of oral and intravenous routes after third molar surgery.
abstract: BACKGROUND
  The purpose of this randomized double-blind study was to compare the efficacy and safety of propacetamol 2 g (an i.v. acetaminophen 1 g formulation) administered as a 2-min bolus injection (n=50) or a 15-min infusion (n=50) with oral acetaminophen 1 g (n=50) or placebo (n=25) for analgesia after third molar surgery in patients with moderate to severe pain after impacted third molar removal.
  
  
  METHODS
  All patients were evaluated for efficacy during the initial 6 h period after treatment administration (T(0)) and for safety during the entire week after T(0).
  
  
  RESULTS
  The onset of analgesia after propacetamol was shorter (3 min for bolus administration, 5 min for 15-min infusion) than after oral acetaminophen (11 min). Active treatments were significantly better for all parameters (pain relief, pain intensity, patient's global evaluation, duration of analgesia) than placebo (P<0.05). Adverse events were more frequent after propacetamol, especially pain at the injection site. Propacetamol bolus resulted in a much higher incidence of local adverse events than the infusion (propacetamol bolus 90% vs propacetamol infusion 52%) with no clinically significant benefits in terms of analgesic efficacy.
  
  
  CONCLUSIONS
  I.V. propacetamol, administered as a 15-min infusion, is a fast-acting analgesic agent. It is more effective in terms of onset of analgesia than a similar dose of oral acetaminophen.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Aarhus University Hospital, DK-800 Aarhus, Denmark. plm@dadlnet.dk
authors.forename: P L
authors.initials: PL
authors.lastname: Moller
authors.forename: S
authors.initials: S
authors.lastname: Sindet-Pedersen
authors.forename: C T
authors.initials: CT
authors.lastname: Petersen
authors.forename: G I
authors.initials: GI
authors.lastname: Juhl
authors.forename: A
authors.initials: A
authors.lastname: Dillenschneider
authors.forename: L A
authors.initials: LA
authors.lastname: Skoglund
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives*; D000284:Administration, Oral; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage* / Q000009:adverse effects; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D008964:Molar, Third / Q000601:surgery*; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000188:drug therapy*; D014081:Tooth Extraction; D014095:Tooth, Impacted / Q000601:surgery
chemical_list: D018712:Analgesics, Non-Narcotic; D000082:Acetaminophen; C063776:propacetamol