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

Abstract

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 the severity of cough, but conversely, 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 strategy: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 4); MEDLINE (January 1966 to December 2006); OLDMEDLINE (1950 to 1965); EMBASE (1980 to December 2006) and the list of references in relevant publications.

Selection criteria: All randomised controlled trials (RCTs) in children and adults comparing any type of OTC cough medication with a 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. Data were extracted from these studies, assessed for methodological quality without disagreement, and analysed using standard methods.

Main results: Four studies were included with a total of 224 participants; 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) 0.36, 95% confidence interval (CI) 0.16 to 0.77; number needed to treat (NNT) 5, 95% CI 3 to 16 for children and OR 0.32, 95% CI 0.13 to 0.75; NNT 5, 95% CI 3 to 19 for adults). In a post hoc analysis combining data for children and adults, again there was also 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 0.33, 95% CI 0.19 to 0.60; NNT 4, 95% CI 3 to 8).

Authors' conclusions: There is insufficient evidence to decide whether OTC medications for cough associated with acute pneumonia are beneficial. Mucolytics may be, but there is insufficient evidence to recommend them as an adjunctive treatment of acute pneumonia. This leaves only theoretical recommendations that OTC medications containing codeine and antihistamines should not be used in young children.