title: The opiate-sparing effect of dipyrone in post-operative pain therapy with morphine using a patient-controlled analgesic system.
abstract: OBJECTIVE
  To determine whether dipyrone has an opiate-sparing effect in post-operative pain therapy compared with placebo during patient-controlled morphine therapy (PCA) and to compare the effects on analgesia and respiratory and coagulation parameters.
  
  
  METHODS
  Randomized, observer-blind, parallel-group, placebo-controlled study.
  
  
  METHODS
  Surgical intensive care unit of a university hospital.
  
  
  METHODS
  106 adult patients who were to undergo abdominal or urological surgery under 90-min standardized inhalational anaesthesia were entered and 103 were included in the efficacy analysis (53 on dipyrone, 50 on placebo).
  
  
  METHODS
  Preprogrammed PCA (0.03 mg morphine/kg per bolus) with either dipyrone (initially 2.0 g i.v. and 1.0 g/2 ml i.v. at 4, 8 and 16 h) or placebo (saline).
  
  
  RESULTS
  Cumulative morphine consumption was calculated automatically during PCA. Pain intensity and pain relief and the investigator's global assessments of efficacy and tolerability were recorded on five-point verbal rating scales. Vital signs, standard laboratory parameters, respiratory rate, partial pressure of carbon dioxide (PCO2) and of oxygen, partial thromboplastin time (PTT) and Quick values were recorded. Total consumption of opiates in the dipyrone group (median 31.6 mg) was significantly less (p = 0.00015) than in the placebo group (median 50.3 mg), while pain relief (area under the curve) AUC was the same for both PCA+dipyrone (median 4.1) and PCA+placebo (median 3.9). Global assessment of efficacy was good to excellent in more than 90% of cases in both groups. Vital signs, respiratory rate, PCO2, PTT and Quick did not differ between groups. Adverse events were mainly nausea and/or vomiting (dipyrone, n = 4; placebo, n = 1); 1 patient in the placebo group had bradycardia. Three serious adverse events were unrelated to study medication. In 1 patient, the PCA programme malfunctioned and had to be changed.
  
  
  CONCLUSIONS
  Concomitant administration of dipyrone with on-demand morphine (PCA) reduces opiate consumption while maintaining post-operative pain relief with a low incidence of side-effects.
authors.affiliation: Klinikum Rechts der Isar, Department of Anesthesiology, Munich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Tempel
authors.forename: B
authors.initials: B
authors.lastname: von Hundelshausen
authors.forename: W
authors.initials: W
authors.lastname: Reeker
mesh_terms: D000328:Adult; D000368:Aged; D016058:Analgesia, Patient-Controlled / Q000379:methods*; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D001777:Blood Coagulation / Q000187:drug effects; D004177:Dipyrone / Q000627:therapeutic use*; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000627:therapeutic use*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D012119:Respiration / Q000187:drug effects; D016037:Single-Blind Method
chemical_list: D000701:Analgesics, Opioid; D000894:Anti-Inflammatory Agents, Non-Steroidal; D004177:Dipyrone; D009020:Morphine