title: Pre-medication with intravenous clonidine suppresses fentanyl-induced cough.
abstract: BACKGROUND
  A reflex cough is often observed after an intravenous bolus of fentanyl. This study was conducted to determine whether pre-treatment with intravenous clonidine could effectively attenuate fentanyl-induced cough.
  
  
  METHODS
  Three hundred ASA I-II patients, aged between 18 and 80 years, undergoing various elective surgeries, were enrolled in this study. All patients were randomly assigned to one of two groups treated with intravenous clonidine 2 microg/kg (clonidine group) or the same volume of normal saline (control group). Intravenous fentanyl (2 microg/kg in 2 s) was injected 2 min after the clonidine or normal saline injection. Changes in the hemodynamics, auditory evoked potentials (AEPs) and Observer Assessment of Alertness/Sedation (OAA/S) rating scale were recorded before and 2 min after the clonidine or normal saline injection and 1 min after the fentanyl injection. The number of coughs 1 min after the fentanyl injection was also recorded.
  
  
  RESULTS
  Patients in the clonidine group showed a significantly lower incidence of cough than those in the control group (17.3% vs. 38.7%, respectively; P < 0.01). The blood pressure was lower in the clonidine group than in the control group. There were no significant differences in AEP or OAA/S rating scale.
  
  
  CONCLUSIONS
  Pre-treatment with intravenous clonidine (2 microg/kg) suppressed the reflex cough induced by fentanyl, with mild hemodynamic changes. Therefore, intravenous clonidine may be a clinically useful method of suppressing fentanyl-induced cough.
authors.affiliation: Department of Anesthesiology, Tri-Service General Hospital and National Defense Medical Center, Taipei, Taiwan.
authors.forename: H-C
authors.initials: HC
authors.lastname: Horng
authors.forename: C-S
authors.initials: CS
authors.lastname: Wong
authors.forename: K-N
authors.initials: KN
authors.lastname: Hsiao
authors.forename: B K
authors.initials: BK
authors.lastname: Huh
authors.forename: C-P
authors.initials: CP
authors.lastname: Kuo
authors.forename: C-H
authors.initials: CH
authors.lastname: Cherng
authors.forename: C-T
authors.initials: CT
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000009:adverse effects*; D001794:Blood Pressure / Q000187:drug effects; D003000:Clonidine / Q000627:therapeutic use*; D003371:Cough / Q000139:chemically induced* / Q000517:prevention & control*; D005260:Female; D005283:Fentanyl / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011229:Preanesthetic Medication; D011446:Prospective Studies
chemical_list: D000316:Adrenergic alpha-Agonists; D000701:Analgesics, Opioid; D003000:Clonidine; D005283:Fentanyl