Over-the-counter (OTC) medications to reduce cough as an adjunct to antibiotics for acute pneumonia in children and adults

Background: Cough is often distressing for patients with pneumonia. Accordingly they often use over-the-counter (OTC) cough medications (mucolytics or cough suppressants). These might provide relief in reducing cough severity, but suppression of the cough mechanism might impede airway clearance and cause harm.

Objectives: To evaluate the efficacy of OTC cough medications as an adjunct to antibiotics in children and adults with pneumonia. Search methods We searched CENTRAL 2013, Issue 12, MEDLINE (January 1966 to January week 2, 2014), OLDMEDLINE (1950 to 1965), EMBASE (1980 to January 2014), CINAHL (2009 to January 2014), LILACS (2009 to January 2014) and Web of Science (2009 to January 2014).

Selection criteria: Randomised controlled trials (RCTs) in children and adults comparing any type of OTC cough medication with placebo, or control medication, with cough as an outcome and where the cough is secondary to acute pneumonia.

Data collection and analysis: We independently selected trials for inclusion. We extracted data from these studies, assessed them for methodological quality without disagreement and analyzed them using standard methods.

Main results: There are no new trials to include in this review update. Previously, four studies with a total of 224 participants were included; one was performed exclusively in children and three in adolescents or adults. One using an antitussive had no extractable pneumonia-specific data. Three different mucolytics (bromhexine, ambroxol, neltenexine) were used in the remaining studies, of which only two had extractable data. They demonstrated no significant difference for the primary outcome of ’not cured or not improved’ for mucolytics. A secondary outcome of ’not cured’ was reduced (odds ratio (OR) for children 0.36, 95% confidence interval (CI) 0.16 to 0.77; number needed to treat to benefit (NNTB) at day 10 = 5 (95% CI 3 to 16) and OR 0.32 for adults (95% CI 0.13 to 0.75); NNTB at day 10 = 5 (95% CI 3 to 19)). In a post hoc analysis combining data for children and adults, again there was no difference in the primary outcome of ’not cured or not improved’ (OR 0.85, 95% CI 0.40 to 1.80) although mucolytics reduced the secondary outcome ’not cured’ (OR 0.34, 95% CI 0.19 to 0.60; NNTB 4, 95% CI 3 to 8). The risk of bias was low or unclear.