What is the recommended dose and duration of Augmentin (amoxicillin/clavulanate) for a typical adult patient with a bacterial sinus infection?

Augmentin Dosing and Duration for Sinus Infection

For adults with acute bacterial sinusitis, prescribe Augmentin 875 mg/125 mg twice daily for 5-10 days, with most patients requiring the full 10-14 day course to ensure complete resolution and prevent relapse. 1

Standard Dosing Regimen

The recommended dose is Augmentin 875 mg/125 mg orally twice daily. 1, 2

• This represents amoxicillin-clavulanate as the first-line antibiotic choice over amoxicillin alone for adults with acute bacterial rhinosinusitis (ABRS). 1
• The addition of clavulanate provides coverage against beta-lactamase-producing organisms like H. influenzae and M. catarrhalis. 1, 2

Treatment Duration

The optimal duration is 5-10 days according to the most recent guidelines, though 10-14 days remains appropriate for many patients. 1

Duration Algorithm:

• 5-7 days: Acceptable for uncomplicated ABRS in adults with good initial response. 1
• 10-14 days: Traditional duration that ensures complete eradication and prevents relapse, particularly appropriate for moderate-to-severe disease. 1, 2, 3
• Continue until symptom-free for 7 days: An alternative endpoint to ensure complete resolution. 1, 3

The evidence shows shorter courses (5-7 days) have fewer adverse effects while maintaining comparable efficacy, but the longer 10-14 day course provides greater certainty of cure. 1

High-Dose Regimen (When Indicated)

Use high-dose Augmentin (2000 mg amoxicillin/125 mg clavulanate twice daily) in specific high-risk scenarios. 1, 2, 4

Indications for High-Dose:

• Recent antibiotic use within the past 4-6 weeks 2, 3, 4
• Moderate-to-severe disease presentation 2, 4
• Geographic areas with high prevalence of resistant organisms or beta-lactamase-producing bacteria 2, 3, 4
• Treatment failure with standard-dose amoxicillin 1, 2
• Suspected resistant pathogens 2, 3

Important caveat: Recent high-quality RCT evidence from 2021 found no benefit of high-dose over standard-dose amoxicillin-clavulanate in adults with clinically diagnosed acute sinusitis, with similar efficacy but potentially more adverse effects. 5 However, guidelines still recommend high-dose for the specific scenarios listed above. 1, 2, 4

Treatment Response Assessment

Reassess the patient at 3 days (72 hours) to determine treatment response. 2, 3, 4

Response Algorithm:

• Improved: Continue the full antibiotic course to completion. 3, 4
• Partial improvement: Continue the full 10-14 day course. 2, 3
• No improvement or worsening: Switch to an alternative antibiotic or reevaluate the diagnosis. 1, 2, 4
• Treatment failure at 7 days: Definitively change antibiotics and consider broader-spectrum coverage. 1

Critical Clinical Considerations

When to Use Augmentin vs. Plain Amoxicillin:

Augmentin is preferred over amoxicillin alone for initial empiric therapy in adults. 1

• The IDSA guideline gives a weak recommendation for amoxicillin-clavulanate over amoxicillin alone in adults (strong recommendation in children). 1
• Use Augmentin specifically for moderate-to-severe illness, recent antibiotic exposure, or high local resistance rates. 2, 4

Watchful Waiting Option:

Consider watchful waiting without antibiotics as an initial strategy if follow-up is assured. 1

• Start antibiotics only if symptoms fail to improve by 7 days or worsen at any time. 1
• This approach is supported by evidence showing 86% of placebo patients improve spontaneously versus 91% with antibiotics (number needed to treat = 11-15). 1
• Adverse events are more common with antibiotics (number needed to harm = 8.1). 1

Common Pitfalls to Avoid

• Do not stop antibiotics early if symptoms improve: Complete the full course to prevent relapse and resistance development. 3
• Do not use standard-dose in high-resistance areas: This leads to treatment failure. 3
• Do not prescribe antibiotics for viral rhinosinusitis: Reserve for true bacterial sinusitis meeting diagnostic criteria (symptoms >10 days, severe symptoms, or worsening after initial improvement). 4
• Do not assess treatment failure before 7 days: Premature switching increases unnecessary antibiotic exposure. 1

Adverse Effects

Diarrhea is the most common adverse effect, occurring in approximately 40% of patients. 5

• Severe diarrhea occurs in 7-8% of patients on standard-dose. 5
• High-dose formulations may increase severe diarrhea rates to 15-16%. 6
• Other common adverse effects include vaginitis and nausea. 7

Penicillin-Allergic Patients

For patients with penicillin allergy, use doxycycline or respiratory fluoroquinolones (levofloxacin, moxifloxacin) as alternatives. 2, 4

• These alternatives have higher bacteriologic failure rates of 20-25%. 4
• Other options include trimethoprim-sulfamethoxazole or cephalosporins (if not severe allergy). 1, 2