title: Emetic effects of morphine and piritramide.
abstract: BACKGROUND
  Successful management of postoperative pain requires that adequate analgesia is achieved without excessive adverse effects. Opioid-induced nausea and vomiting is known to impair patients' satisfaction, but there are no studies providing sufficient power to test the hypothesis that the incidence of opioid-induced nausea and vomiting differs between micro -opioid receptor agonists. Thus, we tested the hypothesis that the incidence of vomiting and nausea differs between morphine and piritramide.
  
  
  METHODS
  In a prospective, randomized, double-blind fashion, we administered either morphine (n=250) or piritramide (n=250) by patient-controlled analgesia (PCA) for postoperative pain relief. We used a bolus dose of 1.5 mg with a lockout time of 10 min. Incidence and intensity (numerical rating scale) of postoperative nausea, vomiting, pain, patient satisfaction (score 0-10), side-effects (score 0-3) and drug consumption were measured.
  
  
  RESULTS
  Mean drug consumption did not differ between the piritramide and morphine groups (30.8 (SD 22.4) mg day(-1) vs 28.4 (21.8) mg day(-1)) during the first postoperative day and there were no significant differences in the overall incidence of nausea (30% vs 27%) and vomiting (19% vs 15%). Intensity of nausea correlated inversely (P=0.01) with morphine consumption but not with piritramide consumption. Pain scores both at rest (2.2 (1.9) vs 2.6 (2)) and during movement (4.4 (2.2) vs 4.9 (2.3)) were slightly but significantly less with morphine.
  
  
  CONCLUSIONS
  Opioid-induced emesis was observed in about one-third of the patients using morphine and piritramide for PCA and the incidence of vomiting was one-half of that. Potential differences in the incidence of vomiting during PCA therapy between these micro-opioid receptor agonists can be excluded.
authors.affiliation: Klinik für Anästhesiologie und Intensivmedizin and Apotheke, Universitätsklinikum Essen, Hufelandstr. 55, D-45122 Essen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Breitfeld
authors.forename: J
authors.initials: J
authors.lastname: Peters
authors.forename: T
authors.initials: T
authors.lastname: Vockel
authors.forename: C
authors.initials: C
authors.lastname: Lorenz
authors.forename: M
authors.initials: M
authors.lastname: Eikermann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016058:Analgesia, Patient-Controlled / Q000009:adverse effects / Q000379:methods; D000701:Analgesics, Opioid / Q000009:adverse effects*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000009:adverse effects*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy; D010892:Pirinitramide / Q000009:adverse effects*; D011182:Postoperative Care / Q000009:adverse effects / Q000379:methods; D020250:Postoperative Nausea and Vomiting / Q000139:chemically induced*; D011446:Prospective Studies
chemical_list: D000701:Analgesics, Opioid; D010892:Pirinitramide; D009020:Morphine