Antibiotics for the common cold

The common cold is considered to be caused by viruses and it has long been believed that antibiotics have no role in treating this condition. In many countries doctors will often prescribe antibiotics for the common cold in the belief that they may prevent secondary bacterial infection and in some cases to respond to patient demand. There is also increasing concern over the resistance of common bacteria to commonly used antibiotics. A crucial step in reducing the use of antibiotics for the common cold is to examine the evidence to see if there is any benefit or if there is benefit for some subgroups or symptom constellations.

(1) To determine the efficacy of antibiotics in comparison with placebo in the treatment of acute upper respiratory tract infections (common colds) in terms of the proportion of patients in whom the clinical outcome was considered to be a reduction in general symptoms and specific nasopharyngeal symptoms. (2) To determine whether there are significant adverse outcomes associated with antibiotic therapy for patients with a clinical diagnosis of acute upper respiratory tract infection.

We searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE, the Family Medicine Database, and reference lists of articles, and we contacted principal investigators. The most recent search was in May 2001 SELECTION CRITERIA: Randomised trials comparing any antibiotic therapy with placebo in acute upper respiratory tract infections with less than 7 days of symptoms

Both reviewers independently assessed trial quality and extracted data.

All analyses used fixed effects unless otherwise stated Main results: Nine trials involving 2249 (2157 analysed) people aged between two months and 79 years (and adults with no upper age limit) years were included. The overall quality of the included trials was variable. People receiving antibiotics did not do better in terms of lack of cure or persistence of symptoms than those on placebo (odds ratio 0.8, 95% confidence interval (95% CI) 0.59 to 1.08). Only one study Taylor et al (1977) specifically reported persistence of clear rhinitis with a small benefit to those on antibiotics. Two studies found a significant benefit for antibiotics compared with placebo for runny nose (clear) odds ratio 0.42 (0.22-0.78). Two studies also found a significant benefit in patients with sore throat odds ratio 0.27 95% CI (0.10-0.74). Only one study reported work time lost with 22% of those on antibiotic treatment and 25% of those on placebo but this was not significant. Adult patients treated with antibiotics had a significant increase in adverse effects (odds ratio 3.6 95% CI 2.21 to 5.89) while there was no significant increase in children odds ratio 0.90 95% CI (0.44-1.82).

There is not enough evidence of important benefits from the treatment of upper respiratory tract infections with antibiotics to warrant their routine use in children or adults and there is a significant increase in adverse effects associated with antibiotic use in adult patients.