Corticosteroids for acute and subacute cough following respiratory tract infection: a systematic review.

BACKGROUND Cough associated with acute respiratory tract infection (RTI) is one of the most common problems managed in primary care. Despite minimal evidence for the use of antibiotics, they continue to be prescribed at great cost and are a significant cause of emerging bacterial resistance. OBJECTIVES To carry out a systematic review of randomized controlled trials to evaluate the effect of corticosteroid therapy in otherwise-healthy adults with acute RTI. METHODS Seven electronic databases and five ongoing trial registers were searched. Studies were eligible if they compared the use of any corticosteroid treatment against a control group in adults with an acute (<3 weeks) or subacute (<8 weeks) cough associated with an RTI but no asthma. Primary outcomes were differences in mean cough and other symptom scores. Secondary outcomes included adverse effects, subsequent diagnosis of asthma and patient satisfaction. RESULTS Four trials (335 participants) investigating the effects of inhaled corticosteroids were identified. None investigated the use of oral corticosteroids. Results were mixed, with two reporting equivalence and two reporting benefits for mean cough score (P = 0.012) and cough frequency (P = 0.047). One reported additional benefits in non-smokers. Adverse events were rare and there were no data on patient satisfaction or the subsequent diagnosis of asthma. Most trials were of unclear risk of bias. Study outcomes were too heterogeneous to meta-analyse. CONCLUSIONS There is insufficient evidence to recommend the routine use of inhaled corticosteroids for acute RTI in adults. However, some trials have shown benefits, suggesting the need for further high-quality, adequately powered trials.