Antibiotics for prolonged moist cough in children


Cough is the most common symptom which presents to doctors. Current recommendations suggest treating prolonged wet cough with antibiotics. We examined whether antibiotics are useful in treating children who have an ongoing persistent wet cough.

Study characteristics

We included randomised controlled trials that compared antibiotics with a placebo (pretend treatment) or control group. The children included in the trials had wet cough lasting more than 10 days.

The evidence is current to September 2017.

We found three studies that varied in a number of ways including different antibiotics (two studies used amoxicillin/clavulanate acid and one used erythromycin) and length of treatment was seven or 14 days.

The mean ages of the children ranged from 21 months to six years.

Key results

This review, involving 190 children with persistent wet cough, found that antibiotics were beneficial in curing the cough. The cure rate was one child cured for every three children treated. Antibiotics also prevented the illness from getting worse, thus avoiding a further course of antibiotics, for one in every four children treated. We found no clear evidence about whether antibiotics were associated with more side effects. We could not assess long-term results.

Reliability of the evidence

The reliability of the evidence was moderate when using antibiotics to cure cough and for illness progression, while it was only low for side effects of medicines.

Take home message

Antibiotics are effective in treating children with chronic (greater than four weeks) wet cough and could be considered when they present to doctors.

Authors' conclusions: 

Evidence suggests antibiotics are efficacious for the treatment of children with chronic wet cough (greater than four weeks) with an NNTB of three. However, antibiotics have adverse effects and this review reported only uncertainty as to the risk of increased adverse effects when they were used in this setting. The inclusion of a more robust study strengthened the previous Cochrane review and its results.

Read the full abstract...

Cough is a frequent symptom presenting to doctors. The most common cause of childhood chronic (greater than fours weeks' duration) wet cough is protracted bacterial bronchitis (PBB) in some settings, although other more serious causes can also present this way. Timely and effective management of chronic wet or productive cough improves quality of life and clinical outcomes. Current international guidelines suggest a course of antibiotics is the first treatment of choice in the absence of signs or symptoms specific to an alternative diagnosis. This review sought to clarify the current evidence to support this recommendation.


To determine the efficacy of antibiotics in treating children with prolonged wet cough (excluding children with bronchiectasis or other known underlying respiratory illness) and to assess risk of harm due to adverse events.

Search strategy: 

We undertook an updated search (from 2008 onwards) using the Cochrane Airways Group Specialised Register, Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, Embase, trials registries, review articles and reference lists of relevant articles. The latest searches were performed in September 2017.

Selection criteria: 

We included randomised controlled trials (RCTs) comparing antibiotics with a placebo or a control group in children with chronic wet cough. We excluded cluster and cross-over trials.

Data collection and analysis: 

We used standard methods as recommended by Cochrane. We reviewed results of searches against predetermined criteria for inclusion. Two independent review authors selected, extracted and assessed the data for inclusion. We contacted authors of eligible studies for further information as needed. We analysed data as 'intention to treat.'

Main results: 

We identified three studies as eligible for inclusion in the review. Two were in the previous review and one new study was included. We considered the older studies to be at high or unclear risk of bias whereas we judged the newly included study at low risk of bias. The studies varied in treatment duration (from 7 to 14 days) and the antibiotic used (two studies used amoxicillin/clavulanate acid and one used erythromycin).

We included 190 children (171 completed), mean ages ranged from 21 months to six years, in the meta-analyses. Analysis of all three trials (190 children) found that treatment with antibiotics reduced the proportion of children not cured at follow-up (primary outcome measure) (odds ratio (OR) 0.15, 95% confidence interval (CI) 0.07 to 0.31, using intention-to -treat analysis), which translated to a number needed to treat for an additional beneficial outcome (NNTB) of 3 (95% CI 2 to 4). We identified no significant heterogeneity (for both fixed-effect and random-effects model the I² statistic was 0%). Two older trials assessed progression of illness, defined by requirement for further antibiotics (125 children), which was significantly lower in the antibiotic group (OR 0.10, 95% CI 0.03 to 0.34; NNTB 4, 95% CI 3 to 5). All three trials (190 children) reported adverse events, which were not significantly increased in the antibiotic group compared to the control group (OR 1.88, 95% CI 0.62 to 5.69). We assessed the quality of evidence GRADE rating as moderate for all outcome measures, except adverse events which we assessed as low quality.