title: Postoperative intramuscular dextromethorphan injection provides postoperative pain relief and decreases opioid requirement after hemorrhoidectomy.
abstract: BACKGROUND
  Previous studies have shown that dextromethorphan (DM) produces an analgesic/antihyperalgesic effect. This study was designed to examine whether postoperative DM intramuscular (i.m.) injection could reduce post-hemorrhoidectomy pain.
  
  
  METHODS
  At the end of the surgery, patients in the study group (n = 30) were given an intramuscular injection of 40 mg DM and 20 mg chlorpheniramine (CPM) while in the study group (n = 30), the patients were given intramuscular 20 mg CPM only. Pethidine (1 mg/kg, i.m.) was prescribed for postoperative pain relief if required. The time to first pethidine injection, total pethidine consumption, worst pain score, and pethidine-related side effects were recorded for 48 h postoperatively.
  
  
  RESULTS
  The time from the end of operation to the first pethidine injection was 5.4 +/- 1.6 h and 17.8 +/- 3.7 h (P = 0.006) in the control group and the study group, respectively. Total pethidine consumption was 139.5 +/- 11.5 mg and 77.5 +/- 12.2 mg (P < 0.001) in the control group and the study group, respectively. The worst VAS score was 7.5 +/- 0.2 and 7.1 +/- 0.2 (P = 0.09) in the control and the study groups, respectively. The number of patients who required pethidine injection was 29 and 21 (P < 0.005) in the control and the study groups, respectively. The number of patients who suffered pethidine-related side effects was 7 and 1 (P < 0.025) in the control and the study groups, respectively.
  
  
  CONCLUSIONS
  We found that intramuscular DM given at the end of operation could provide good postoperative pain relief and decrease the pethidine requirement after hemorrhoidectomy.
authors.affiliation: Department of Anesthesiology, Tri-Service General Hospital, Taipei, Taiwan, R.O.C.
authors.forename: F L
authors.initials: FL
authors.lastname: Chang
authors.forename: C T
authors.initials: CT
authors.lastname: Wu
authors.forename: C C
authors.initials: CC
authors.lastname: Yeh
authors.forename: T C
authors.initials: TC
authors.lastname: Lin
authors.forename: S T
authors.initials: ST
authors.lastname: Ho
authors.forename: C S
authors.initials: CS
authors.lastname: Wong
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D003915:Dextromethorphan / Q000627:therapeutic use*; D005260:Female; D006484:Hemorrhoids / Q000601:surgery*; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008614:Meperidine / Q000627:therapeutic use*; D008875:Middle Aged; D010149:Postoperative Pain / Q000188:drug therapy*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors
chemical_list: D000701:Analgesics, Opioid; D016194:Receptors, N-Methyl-D-Aspartate; D003915:Dextromethorphan; D008614:Meperidine