Antibiotics in uncomplicated lower respiratory tract infection: Is it necessary?

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Remember the last time you were sick and coughing and your doctor prescribed you with some antibiotics and you felt better after a few days? Ever wondered whether you would have felt any different without the antibiotics?




Professor Little and coauthors conducted a research which was published in The Lancet journal, 19 December 2012 to assess this.

• 16 primary care network across 12 European countries
• 2061 patients with acute lower respiratory tract infection 
• Main symptom of cough ≤28 days in duration
• Patient with suspected pneumonia excluded (the aim was to include only uncompliated lower respiratory tract infection, such as acute bronchitis)
• 1038 assigned to the antibiotic amoxicillin (1g three times daily for 7 days), 1023 to placebo group
• Mean age 49 years (~40% male, ~60% female)
• Patient completed a daily symptom diary for 28 days

RESULTS - comparing the antibiotic group versus the placebo group

• Duration of symptoms labeled as "moderately bad" or worse: NO DIFFERENCE 
• hazard ratio 1·06, 95% CI 0·96-1·18; p=0·229
• Mean symptom severity: NO DIFFERENCE
• 1·69 (placebo) vs 1·62 (amoxicillin); difference −0·07 [95% CI −0·15 to 0·007]; p=0·074

• New or worsening symptoms were significantly less common in the amoxicillin group than in the placebo group 
• 162 (15·9%) of 1021 patients vs 194 (19·3%) of 1006; p=0·043
• 30 patients needed to be treated with amoxicillin before this benefit is seen

• Side effects of nausea, rash, or diarrhoea were significantly more common in the amoxicillin group than in the placebo group (number needed to harm 21, 95% CI 11-O74; p=0·025)
• One case of anaphylaxis was with amoxicillin
• Two patients in the placebo group and one in the amoxicillin group hospitalized
•  No study-related deaths

Even looking specifically at only adults age 60 years or older, the antibiotic amoxicillin did not significantly improve symptoms.

SUMMARY:

• In adults with uncomplicated lower respiratory tract infection (ie. not pneumonia), the antibiotic amoxicillin does not improve the symptoms
• One (lucky) patient in every 30 patients treated with amoxicillin will be less likely to develop new or worsening symptoms
• At the price of being more likely to develop side effects such as nausea, rash, and diarrhea, and rare chance of potentially life threatening allergic reaction

Bear in mind:

• You still need to see your doctor to make sure you don't have pneumonia
• In this study, they looked at amoxicllin. There are various other antibiotics that can be used