Amoxicillin for acute lower respiratory tract infection in primary care: subgroup analysis of potential high-risk
Michael Moore1, Beth Stuart, Samuel Coenen
1University of Southampton, Southampton, UK.
Background:
Antibiotics are of limited overall clinical benefit for uncomplicated lower respiratory tract infection (LRTI) but there is uncertainty about their effectiveness for patients with features associated with higher levels of antibiotic prescribing.
Aim:
To estimate the benefits and harms of antibiotics for acute LRTI among those producing coloured sputum, smokers, those with fever or prior comorbidities, and longer duration of prior illness.
Design And Setting:
Secondary analysis of a randomised controlled trial of antibiotic placebo for acute LRTI in primary care.
Method:
Two thousand and sixty-one adults with acute LRTI, where pneumonia was not suspected clinically, were given amoxicillin or matching placebo. The duration of symptoms, rated moderately bad or worse (primary outcome), symptom severity on days 2-4 (0-6 scale), and the development of new or worsening symptoms were analysed in pre-specified subgroups of interest. Evidence of differential treatment effectiveness was assessed in prespecified subgroups by interaction terms.
Results:
No subgroups were identified that were significantly more likely to benefit from antibiotics in terms of symptom duration or the development of new or worsening symptoms. Those with a history of significant comorbidities experienced a significantly greater reduction in symptom severity between days 2 and 4 (interaction term -0.28, P = 0.003; estimated effect of antibiotics among those with a past history -0.28 [95% confidence interval = -0.44 to -0.11], P = 0.001), equivalent to three people in 10 rating symptoms as a slight rather than a moderately bad problem. For subgroups not specified in advance antibiotics provided a modest reduction in symptom severity for non-smokers and for those with short prior illness duration (<7 days), and a modest reduction in symptom duration for those with short prior illness duration.
Conclusion:
There is no clear evidence of clinically meaningful benefit from antibiotics in the studied high-risk groups of patients presenting in general practice with uncomplicated LRTIs where prescribing is highest. Any possible benefit must be balanced against the side-effects and longer-term effects on antibiotic resistance.
Insights
Antibiotics offer limited benefit for uncomplicated lower respiratory tract infections (LRTI). Even in high-prescribing groups, evidence for significant advantages is lacking, necessitating careful consideration of side effects and antibiotic resistance.
Area of Science:
- Infectious Diseases
- General Practice
- Clinical Pharmacology
Background:
- Antibiotics provide limited clinical benefit for uncomplicated lower respiratory tract infections (LRTI).
- Uncertainty exists regarding antibiotic effectiveness in patients with specific features prompting higher prescribing rates.
Purpose of the Study:
- To assess antibiotic benefits and harms in acute LRTI patients with specific characteristics.
- Investigated subgroups including those with colored sputum, smokers, fever, comorbidities, or prolonged illness duration.
Main Methods:
- Secondary analysis of a randomized controlled trial comparing antibiotics (amoxicillin) to placebo for acute LRTI in primary care.
- 2061 adults with uncomplicated LRTI were analyzed for symptom duration, severity, and new/worsening symptoms in pre-specified subgroups.
Main Results:
- No subgroups showed significantly greater benefit from antibiotics regarding symptom duration or new/worsening symptoms.
- Patients with comorbidities experienced reduced symptom severity (days 2-4) with antibiotics.
- Modest benefits in symptom severity or duration were observed in non-smokers and those with shorter illness duration (<7 days).
Conclusions:
- No clear clinically meaningful benefit from antibiotics was found in high-risk groups with uncomplicated LRTIs in general practice.
- Potential benefits must be weighed against antibiotic side effects and the development of antibiotic resistance.
Related Concept Videos
01:29Microbiota of the Respiratory Tract
01:30Pneumonia III: Complications and Assessment
01:14Atypical Pneumonia
01:25Clinical Significance of Antibiotic Resistance
01:17Drugs Used in Lower Respiratory Disorders: Overview
Bronchodilators, the first step of respiration enhancement, come in various forms, each with its own mechanism...
01:16Drugs Used in Upper Respiratory Disorders: Overview
Antihistamines (e.g., Benadryl) block histamines from binding. Histamines are chemicals released during an allergic reaction in the body. As a...