title: The use of different doses of metamizol for post-operative analgesia in dogs.
abstract: OBJECTIVE
  To evaluate the post-operative analgesic effect of metamizol (dipyrone) administered intravenously at three different doses (15 mg kg(-1), 25 mg kg(-1) and 35 mg kg(-1)) compared to placebo in dogs undergoing ovariohysterectomy.
  
  
  METHODS
  Prospective, comparative, randomized, blinded trial.
  
  
  METHODS
  Forty healthy bitches, aged 1-6 years, weighing 10-35 kg
  
  
  METHODS
  The animals were randomly divided into four groups and received their respective treatments immediately after surgery: placebo group (0.9% saline solution), D15 group (metamizol 15 mg kg(-1) IV), D25 group (metamizol 25 mg kg(-1) IV), D35 group (metamizol 35 mg kg(-1) IV). The following variables were measured: sedation, pulse rate (PR), respiratory rate (f(R)), arterial blood pressure (ABP), plasma catecholamines, serum cortisol, blood urea nitrogen (BUN) and creatinine metabolites, albumin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), hemogram, platelet counts and level of analgesia which was assessed by visual analog (VAS), descriptive and behavioral scales. Patients were monitored for 48 hours after the administration of the analgesic agent. Rescue analgesia (tramadol, 2 mg kg(-1), intramuscularly) was provided for animals with pain scores ≥4, as determined by the VAS or descriptive scale.
  
  
  RESULTS
  The D25 and D35 groups showed equivalent post-operative analgesia, as shown by decreased pain scores, according to the three different pain scales, and fewer animals that required rescue analgesia. Significantly lower serum cortisol concentrations were observed in the D25 and D35 groups when compared to the placebo and D15 groups. No hematologic, renal, hepatic or clinical adverse effects were observed during the treatment.
  
  
  CONCLUSIONS
  Metamizol administered intravenously at 25 or 35 mg kg(-1) can provide adequate post-operative analgesia in bitches undergoing ovariohysterectomy.
authors.affiliation: School of Veterinary Medicine and Zootechnic, University of São Paulo, São Paulo, Brazil. pg.anestesiologia@incor.usp.br
authors.forename: Vivianne H
authors.initials: VH
authors.lastname: Imagawa
authors.forename: Denise T
authors.initials: DT
authors.lastname: Fantoni
authors.forename: Angélica C
authors.initials: AC
authors.lastname: Tatarunas
authors.forename: Sandra
authors.initials: S
authors.lastname: Mastrocinque
authors.forename: Tatiana F
authors.initials: TF
authors.lastname: Almeida
authors.forename: Fernando
authors.initials: F
authors.lastname: Ferreira
authors.forename: Irimar P
authors.initials: IP
authors.lastname: Posso
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage*; D004177:Dipyrone / Q000008:administration & dosage*; D004285:Dogs / Q000601:surgery*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007044:Hysterectomy / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D010052:Ovariectomy / Q000662:veterinary; D010147:Pain Measurement / Q000662:veterinary; D010149:Postoperative Pain / Q000188:drug therapy / Q000662:veterinary*; D011446:Prospective Studies; D016037:Single-Blind Method; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D004177:Dipyrone