title: Dose-response relationship with increasing doses of dextromethorphan for children with cough.
abstract: BACKGROUND
  The efficacy of dextromethorphan (DM) for treating acute cough is uncertain, and its use is not supported by the American Academy of Pediatrics. Nevertheless, DM is often administered to children as an antitussive. DM dosages are based on age rather than body weight, resulting in substantial variability in the relative amount of drug administered.
  
  
  OBJECTIVE
  The aim of this work was to determine whether a dose-response relationship existed among a group of children administered a single nocturnal dose of DM for cough due to an upper respiratory tract infection.
  
  
  METHODS
  As part of a larger double-blind, placebo-controlled trial of over-the-counter cough medications, children received DM. The administered doses (per manufacturer recommendations) were as follows: ages 2 to 5 years, 7.5 mg; ages 6 to 11 years, 15 mg; and ages 12 to 18 years, 30 mg. This resulted in a range of 0.35 to 0.94 mg/kg per dose. Subjective parental assessments of cough and sleep were obtained using a 7-point Likert-type scale that compared symptoms after medication with symptoms during the prior night (without medication). Three dose ranges were compared as a subset analysis of the group that received DM.
  
  
  RESULTS
  Thirty-three patients (19 girls, 14 boys; median [interquartile range] age, 4.90 [2.90-6.80] years; age range, 2.10-16.50 years) received DM and completed the study. No significant differences were found for any of the outcome measures when comparing the effects of different doses of DM, but our observations suggested somewhat more symptomatic relief for patients receiving medium-dose DM (0.45 to <0.60 mg/kg per dose) or high-dose (HD) DM (0.60-0.94 mg/kg per dose) compared with low-dose DM (0.35 to <0.45 mg/kg per dose). Adverse events occurred most often in the HD group.
  
  
  CONCLUSIONS
  Although no statistically significant differences were detectable for the outcomes studied, our observations suggest the potential for improved clinical symptom control with increasing doses of DM. Our findings may further suggest that a dose of 0.5 mg/kg should be considered in future assessments of the antitussive effect of DM in pediatric studies, to balance symptomatic relief with the avoidance of adverse events.
authors.affiliation: Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, Pennsylvania, USA. ipaul@psu.edu
authors.forename: Ian M
authors.initials: IM
authors.lastname: Paul
authors.forename: Michele L
authors.initials: ML
authors.lastname: Shaffer
authors.forename: Katharine E
authors.initials: KE
authors.lastname: Yoder
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Sturgis
authors.forename: Mark S
authors.initials: MS
authors.lastname: Baker
authors.forename: Cheston M
authors.initials: CM
authors.lastname: Berlin
mesh_terms: D000293:Adolescent; D000996:Antitussive Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D003371:Cough / Q000188:drug therapy* / Q000209:etiology; D003625:Data Collection; D003915:Dextromethorphan / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D012141:Respiratory Tract Infections / Q000150:complications; D012720:Severity of Illness Index; D012890:Sleep / Q000187:drug effects; D016896:Treatment Outcome
chemical_list: D000996:Antitussive Agents; D003915:Dextromethorphan