What are the indications for antibiotics in acute asthma exacerbation?

From the Guidelines

Antibiotics are not routinely recommended for asthma exacerbations unless there is clear evidence of a bacterial infection. Most asthma exacerbations are triggered by viral infections or environmental factors, not bacteria, making antibiotics ineffective in most cases 1. If a bacterial infection is suspected (such as pneumonia or sinusitis), appropriate antibiotics might include amoxicillin-clavulanate 875/125 mg twice daily for 5-7 days, azithromycin 500 mg on day 1 followed by 250 mg daily for 4 days, or doxycycline 100 mg twice daily for 5-7 days. Signs that might warrant antibiotics include fever, purulent sputum, and evidence of consolidation on examination or imaging. Unnecessary antibiotic use can lead to antibiotic resistance, disruption of gut microbiota, and side effects without providing benefit.

Key Considerations

• The cornerstone of asthma exacerbation treatment includes short-acting beta-agonists (like albuterol), systemic corticosteroids (like prednisone 40-60 mg daily for 5-7 days), and oxygen if needed 1.
• Addressing the underlying trigger and optimizing controller medications are essential for preventing future exacerbations.
• Patients presenting with an asthma exacerbation should be evaluated and triaged immediately, with treatment instituted promptly on determination of a moderate, severe, or life-threatening exacerbation 1.

Treatment Approach

• Primary treatment consists of administration of oxygen, inhaled b2-agonists, and systemic corticosteroids, with the dose and frequency of administration, along with the frequency of patient monitoring, dependent on the severity of the exacerbation 1.
• Patients can generally be discharged if FEV1 or PEF results are 70% or more of predicted value or personal best and symptoms are minimal or absent, with a prescription for 3 to 10 days of corticosteroid therapy to reduce the risk of recurrence 1.

From the Research

Antibiotics for Asthma Exacerbation

• The use of antibiotics for asthma exacerbation is a topic of ongoing debate, with some studies suggesting that antibiotics may improve symptoms and peak expiratory flow rate (PEFR) at follow-up compared with standard care or placebo 2.
• However, the evidence is limited and inconsistent across studies, and the quality of the outcomes is often downgraded due to suspicion of publication bias, indirectness, imprecision, and poor methodological quality of studies 2.
• A study published in 2019 found that low-dose azithromycin is an effective therapy for persistent asthma and also reduces asthma exacerbations in patients with severe asthma, regardless of how this is defined 3.
• Another study published in 2018 found that azithromycin is non-inferior to amoxicillin-clavulanate for resolving exacerbations in children with non-severe bronchiectasis, but may have a longer exacerbation duration and a risk of inducing macrolide resistance 4.
• The use of biomarkers, such as procalcitonin, may be helpful in deciding whether or not to give antibiotics for asthma exacerbation, but more research is needed to evaluate the usage of these kinds of biomarkers 5.
• A review published in 2001 found that the role of antibiotics in the treatment of acute asthma is difficult to assess from the current literature, and recommendations regarding antibiotic use in acute asthma will remain consensus-driven until more research is conducted 6.

Key Findings

• Antibiotics may improve symptoms and PEFR at follow-up compared with standard care or placebo in patients with asthma exacerbation 2.
• Azithromycin is an effective therapy for persistent asthma and reduces asthma exacerbations in patients with severe asthma 3.
• Azithromycin is non-inferior to amoxicillin-clavulanate for resolving exacerbations in children with non-severe bronchiectasis 4.
• Biomarkers, such as procalcitonin, may be helpful in deciding whether or not to give antibiotics for asthma exacerbation 5.

Study Limitations

• The evidence is limited and inconsistent across studies 2.
• The quality of the outcomes is often downgraded due to suspicion of publication bias, indirectness, imprecision, and poor methodological quality of studies 2.
• More research is needed to evaluate the usage of biomarkers, such as procalcitonin, in deciding whether or not to give antibiotics for asthma exacerbation 5.