What antibiotics are effective for acute respiratory infections (ARIs)?

From the Guidelines

The most effective antibiotics for acute respiratory infections (ARIs) are amoxicillin, azithromycin, and amoxicillin-clavulanate, which target common bacterial pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, and Group A Streptococcus. When choosing an antibiotic, it's essential to consider the specific type of infection, local resistance patterns, patient factors like allergies and comorbidities, and symptom severity 1. For adults with pneumonia, amoxicillin 500-875 mg three times daily for 5-7 days is standard, while azithromycin 500 mg on day one followed by 250 mg daily for 4 more days is an alternative for those with penicillin allergies. Some key points to consider when prescribing antibiotics for ARIs include:

• Amoxicillin is typically first-line for community-acquired pneumonia and streptococcal pharyngitis
• Azithromycin is an alternative for those with penicillin allergies
• Amoxicillin-clavulanate is often prescribed for sinusitis that persists beyond 10 days
• Antibiotic selection should be guided by local resistance patterns, patient factors, and symptom severity
• Acute bronchitis is usually viral and doesn't require antibiotics It's also important to note that antibiotics are rarely effective for acute cough and are not indicated for acute cough from the common cold, acute bronchitis, asthma, mild exacerbations of chronic bronchitis related to smoking, or environmental irritants 1. Ultimately, the choice of antibiotic should be based on the most recent and highest-quality evidence, taking into account the specific clinical context and patient needs.

From the FDA Drug Label

Levofloxacin has in vitro activity against Gram-negative and Gram-positive bacteria fections as described in Indications and Usage (1): Gram-PositiveBacteria Enterococcus faecalis Staphylococcus aureus (methicillin-susceptible isolates) Staphylococcus epidermidis (methicillin-susceptible isolates) Staphylococcus saprophyticus Streptococcus pneumoniae (including multi-drug resistant isolates [MDRSP] ) Streptococcus pyogenes Gram-Negative Bacteria Enterobacter cloacae Escherichia coli Haemophilus influenzae Haemophilus parainfluenzae Klebsiella pneumoniae Legionella pneumophila Moraxella catarrhalis Proteus mirabilis Pseudomonas aeruginosa Serratia marcescens Other Bacteria Chlamydophila pneumoniae Mycoplasma pneumoniae

Effective antibiotics for acute respiratory infections (ARIs) include:

• Levofloxacin, which is effective against Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydophila pneumoniae, and Mycoplasma pneumoniae 2
• Other antibiotics may be effective, but the FDA label does not provide direct information about their use for ARIs. Note that the effectiveness of an antibiotic depends on the specific causative pathogen and its susceptibility to the antibiotic.

From the Research

Effective Antibiotics for Acute Respiratory Infections (ARIs)

• Macrolides, such as azithromycin, are effective in treating ARIs, including acute bronchitis and pneumonia 3, 4, 5
• Beta-lactams, including amoxicillin and amoxicillin/clavulanic acid, are also effective in treating ARIs, including community-acquired pneumonia and acute rhinosinusitis 6, 7
• Doxycycline is another antibiotic that can be used to treat ARIs, although its effectiveness may vary depending on the specific infection and causative pathogen 6
• Beta-lactam/beta-lactamase inhibitor combinations, such as amoxicillin/clavulanic acid, can provide coverage for common respiratory pathogens, including penicillin and macrolide nonsusceptible Streptococcus pneumoniae, as well as beta-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis 6

Comparison of Antibiotics

• Azithromycin has been shown to be as effective as amoxicillin/clavulanic acid in treating acute lower respiratory tract infections, with a shorter treatment duration and fewer adverse events 4, 5
• Clarithromycin has been shown to be equivalent to amoxicillin/clavulanate in treating acute exacerbation of chronic bronchitis, with improved gastrointestinal tolerability 7
• The choice of antibiotic may depend on factors such as the severity of the infection, the presence of underlying medical conditions, and the likelihood of antibiotic resistance 6, 3