title: Effect of topical diphenhydramine on the laryngeal chemoreflex.
abstract: OBJECTIVE
  To study diphenhydramine nebulization as a clinically applicable method for blunting laryngeal chemoreflex (LCR)-associated apnea.
  
  
  METHODS
  Fourteen piglets aged 15 to 18 days were studied. In 7 piglets, diphenhydramine hydrochloride (5.0 mg/kg) was nebulized onto the laryngeal mucosa after a baseline response was obtained.
  
  
  RESULTS
  After a 10-minute waiting period, the mean +/- SD LCR-induced apnea duration decreased from 29 +/- 13 seconds in the control animals to 15 +/- 5 seconds in the treated group (P = .02, 1-factor analysis of variance). After 1 hour, no treatment effect was seen.
  
  
  CONCLUSIONS
  Nebulization of diphenhydramine can effectively reduce LCR-induced apnea for a short time. Nebulization of longer-acting agents may provide an effective prophylaxis of LCR-induced apnea.
authors.affiliation: University of Minnesota, Minneapolis, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Boyer
authors.forename: D H
authors.initials: DH
authors.lastname: Downs
authors.forename: G S
authors.initials: GS
authors.lastname: Goding
authors.forename: K J
authors.initials: KJ
authors.lastname: Pernell
mesh_terms: D000287:Administration, Topical; D000336:Aerosols; D000818:Animals; D001049:Apnea / Q000503:physiopathology; D001794:Blood Pressure; D004155:Diphenhydramine / Q000008:administration & dosage* / Q000494:pharmacology; D004576:Electromyography; D006634:Histamine H1 Antagonists / Q000008:administration & dosage* / Q000494:pharmacology; D007821:Laryngeal Muscles / Q000502:physiology; D007830:Larynx / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D012018:Reflex / Q000187:drug effects*; D012119:Respiration; D012965:Sodium Chloride / Q000008:administration & dosage; D013552:Swine
chemical_list: D000336:Aerosols; D006634:Histamine H1 Antagonists; D012965:Sodium Chloride; D004155:Diphenhydramine