Table 3

Characteristics of RCTs of OTC cough preparations versus placebo for the treatment of acute cough

ParticipantsInterventionOutcomeResults
StudyParticipant characteristics (no., age, sex, smoking status), setting, countryDefinition of illnessDrugDosageFrequencyTreatment durationMethod of measuring main cough outcomeEfficacyAdverse effects
Antitussives
Taylor et al957 children, mean age 4.7 years (range 18 months to 12 years), 53% boys, 82% white, private paediatric practices, USANight cough due to URTI1. Dextromethorphan/guaiphenesin15mg/5ml (dextromethorphan), 100mg/5ml (guaiphenesin)Single dose at bedtime3 nightsParent questionnaire, cough score from 0 to 4Mean reductions in cough scores 2.2 (codeine) and 2.1 (dextromethorphan) versus 2.2 in the placebo group, p=0.52 and 0.97 respectivelyMainly drowsiness, diarrhoea and hyperactivity: placebo: 7/13 (54%), dextromethorphan: 6/19 (32%), p=0.2, codeine: 5/17 (29%), p=0.8
2. Codeine/guaiphenesin10mg/5ml (codeine)
100mg/5ml (age 18 months to 5 years: 2.5ml; 6 to 11 years: 5ml)
Mucolytics
Nespoli et al1040 children, age range 2 to 12 years (median 7.5 years), paediatric clinic, ItalyAcute febrile bronchitisLetosteine25mgThree times daily10 daysCough score from 0 to 3, unclear how measuredLower cough scores in the active treatment group compared to placebo (difference between groups ranging from 0.1 to 0.3 points from day four to 10, p<0.01)No side effects in both groups reported
Antihistamineā€“decongestant combinations
Clemens et al1159 preschool children (6 months to 5 years, mean age 2 years), 4 paediatric offices, USAURTI of less than 7 days durationBrompheniramine2mg/5ml4-hourly `as needed'48 hoursParent questionnaire, 7-point Likert scale, also counted `responses' after each doseMean cough scores 4.67 (active treatment) and 4.57 (placebo), p=0.53.Not reported. Higher proportion asleep in the active treatment group (41/88 responses = 47%) compared to placebo (28/65 responses = 26.5%)
Phenylpropanolamine12.5mg/5ml(6 mths to 1 year: Ā½12 teaspoon, 2 to 5 years: 1 teaspoon)
Hutton et al1296 inner-city black children, 6 months to 5 years, mean age about 2 years, primary care clinic, USASymptoms of URTIBrompheniramine4mg/5mlThree times daily2 days9-point symptom score by parents or physician, follow-up telephone interviews`Improvement' reported in 20/30 (67%) in the active treatment group compared to 14/24 (58%) in the placebo group and 21/30 (70%) in the group receiving treatment (p=0.5 and 0.8 respectively)Loose stools (n=1) in the placebo group and hyperactivity in the active treatment group (n=1)
Phenylephrine5mg/5ml
Propanolamine5mg/5ml(doses calculated to achieve brompheniramine dosage of 0.5 to 0.75 mg/kg/day)
Other combinations
Reece et al1343 children, mean age 3.6 years (range 2 months to 12 years), 58% boys, ambulatory private practice, USACough due to URTI1. Triaminicol syrup:UnclearUnclearParent assessment`Satisfactory' response in 11/16 (69%) and 9/13 (69%) in the intervention groups compared to 8/14 (57%) in the placebo group, p=0.5 for both comparisons*Not reported
Phenylpropanolamine Pheniramine, Pyrilamine Dextromethorphan Ammonium chloride12.5mg, 6.25mg, 6.25mg, 15mg, 90mg
2. Dorcol paediatric cough syrup:
Dextromethorphan7.5mg
Phenylpropanolamine8.75mg
Glyceryl guaiacolate37.5mg
Alcohol5%
ParticipantsInterventionOutcomeResults
Hypothesis stated a priori?Participant characteristics (no., age, sex, smoking status), setting, countryDefinition of illnessDrugDosageFrequencyTreatment durationMethod of measuring main cough outcomeEfficacyAdverse effects mg/kg/day
*p values calculated from percentages.
URTI, upper respiratory tract infection.
Antihistamines
Sakchainanont et al14143 children under 5 years, mean age 23 months (range 1.5 to 60 months), 50% girls, paediatric outpatients, ThailandCommon coldGroup I: clemastine0.05mg/kg/dayTwice daily3 daysParent assessment using 4-level symptom scoreCough `improved' in 19/48 (39.6%) in the clemastine group and in 19/48 (39.6%) in the chlorpheniramine group compared with 13/47 (27.6%) taking placebo (p=0.2)Increased drowsiness and sleepiness reported in 20% or children with no differences between treatment groups
Group II: chlorpheniramine0.35mg/kg/dayThree times daily