Augmentin Dosing for Possible Pneumonia in Adult with Influenza
For an adult with influenza and possible pneumonia already on Tamiflu, start Augmentin 875 mg/125 mg twice daily for 7 days, taken at the start of meals to minimize gastrointestinal side effects. 1
Rationale for Adding Antibiotics
The decision to add antibiotics to ongoing oseltamivir therapy should be based on clinical evidence of bacterial superinfection, not reflexive prescribing. Common bacterial superinfections with influenza include Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae, all of which are covered by amoxicillin-clavulanate. 2
Key indicators that warrant antibiotic therapy include:
- New consolidation on chest imaging 2
- Purulent sputum production 2
- Clinical deterioration despite oseltamivir treatment 2
- Elevated inflammatory markers suggesting bacterial infection 2
Important caveat: The absence of consolidation on chest X-ray argues against bacterial pneumonia, and diminished breath sounds alone can occur with influenza viral pneumonia and does not mandate antibiotics. 2 The IDSA and ACP recommend against reflexively adding antibiotics for viral influenza symptoms alone, as this contributes to antimicrobial resistance. 2
Dosing Specifications
Standard adult dosing for respiratory tract infections:
- Augmentin 875 mg/125 mg orally every 12 hours 1
- Alternative: 500 mg/125 mg every 8 hours for more severe infections 1
- Duration: 7 days 3, 4
Administration instructions:
- Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance 1
- May be taken without regard to meals, but meal administration is strongly preferred 1
Clinical Efficacy
Amoxicillin-clavulanate provides broad-spectrum coverage against community-acquired respiratory pathogens, including beta-lactamase-producing H. influenzae and M. catarrhalis, as well as S. pneumoniae with reduced penicillin susceptibility. 5 The combination has demonstrated clinical success rates of approximately 93% in community-acquired pneumonia when compared to other antibiotics. 3
Concurrent Use with Oseltamivir
Continue the oseltamivir (Tamiflu) at 75 mg twice daily for the full 5-day course, as this provides mortality benefit and reduces complications even in patients with bacterial superinfection. 2, 6 There are no significant drug interactions between oseltamivir and amoxicillin-clavulanate. 2
Renal Function Considerations
For patients with normal renal function: Use standard dosing as above. 1
If creatinine clearance is impaired: Dose adjustments may be necessary for both medications, though specific guidance for Augmentin in renal impairment is not provided in the standard FDA labeling for mild-moderate impairment. 1
Expected Adverse Effects
Common side effects of Augmentin:
- Gastrointestinal symptoms (diarrhea, nausea) are most common 3
- Taking with food significantly reduces these effects 1
Oseltamivir side effects to monitor concurrently:
- Nausea and vomiting (occur in approximately 10-15% of patients) 2, 6
- These are transient and rarely lead to discontinuation 2
Critical Pitfalls to Avoid
Do not substitute tablet formulations incorrectly: Two 250 mg/125 mg tablets are NOT equivalent to one 500 mg/125 mg tablet, as both contain the same amount of clavulanic acid (125 mg). 1
Do not withhold oseltamivir while waiting for influenza confirmation in high-risk patients, as delays reduce effectiveness. 2 However, also do not reflexively add antibiotics without clinical evidence of bacterial superinfection. 2