Augmentin Dosing for Sinus Infection
For adults with acute bacterial sinusitis, prescribe standard-dose amoxicillin-clavulanate 875 mg/125 mg twice daily for 7 days, taken at the start of meals. Recent high-quality evidence shows no benefit from high-dose formulations and standard-dose amoxicillin alone may be equally effective with fewer adverse effects 1.
Adult Dosing
Standard Regimen
- Amoxicillin-clavulanate 875 mg/125 mg twice daily for 7 days 2
- Take at the start of meals to minimize GI intolerance and enhance clavulanate absorption 2
- This is the most appropriate first-line choice when antibiotic therapy is indicated
When to Consider Antibiotics
Only prescribe antibiotics when acute bacterial rhinosinusitis (ABRS) is diagnosed based on:
- Symptoms persisting >10 days without improvement, OR
- Worsening symptoms within 10 days after initial improvement ("double worsening") 3
- Symptoms include purulent nasal discharge PLUS facial pain/pressure or nasal obstruction
High-Dose Formulations: Not Recommended
The extended-release formulation (2000 mg/125 mg twice daily) showed no superiority over standard dosing in recent trials 4, 5. A 2021 randomized trial found no difference in improvement rates (44.3% vs 36.4%, P=0.35) between standard and high-dose regimens 4. High-dose immediate-release formulations increased severe diarrhea risk (15.8% vs 4.8%, P=0.048) without clear benefit 5.
Alternative: Consider Amoxicillin Alone
A 2026 observational study of 234,608 patients found no difference in treatment failure between amoxicillin-clavulanate and amoxicillin alone (3.0% vs 3.1%, RR 0.96) 1. Importantly, amoxicillin-clavulanate was associated with higher rates of:
- Yeast infections (1.1% vs 0.8%, RR 1.40)
- C. difficile infections (0.04% vs 0.02%, RR 2.14) 1
This suggests amoxicillin 875 mg twice daily may be preferred for uncomplicated cases to minimize adverse effects while maintaining efficacy.
Pediatric Dosing (≥3 months)
Standard Approach
For children ≥2 years with mild-to-moderate uncomplicated sinusitis:
- Amoxicillin 45 mg/kg/day divided twice daily 6
- Reserve for children NOT in daycare and no recent antibiotic use (within 4 weeks)
High-Risk Children
For children with moderate-to-severe illness, age <2 years, daycare attendance, or recent antibiotic exposure:
- Amoxicillin-clavulanate 90 mg/kg/day (of amoxicillin component) with 6.4 mg/kg/day clavulanate, divided twice daily 6, 7
- Maximum 2 g per dose
- Use AUGMENTIN ES-600 formulation (600 mg/5 mL) 2
Duration
- Minimum 10 days of treatment 6, 2, 7
- Alternative strategy: Continue for 7 days after symptom resolution (results in minimum 10-day course) 6
Special Considerations for Children
- Do NOT substitute standard Augmentin suspensions for ES-600 formulation—they contain different clavulanate concentrations and are not interchangeable 2
- For vomiting children or poor adherence: Single dose ceftriaxone 50 mg/kg IV/IM, then switch to oral if improved at 24 hours 6
Renal Impairment Adjustments
Dose with caution and monitor hepatic function regularly in patients with hepatic impairment 2. The FDA label emphasizes this but does not provide specific renal dosing adjustments for the standard formulations discussed. In clinical practice, reduce frequency for severe renal impairment (CrCl <30 mL/min).
Critical Pitfalls to Avoid
Overprescribing antibiotics: Most acute sinusitis is viral. Only 2% of cases develop bacterial superinfection 3. Wait for the 10-day mark or double-worsening pattern before prescribing.
Excessive duration: 75% of first-line agents are prescribed for >7 days despite guidelines recommending 7 days 8. Longer courses increase adverse effects without benefit.
Using imaging routinely: Do NOT obtain CT or X-rays for uncomplicated cases 3. Reserve imaging only for suspected complications or alternative diagnoses.
Wrong formulation in children: The ES-600 suspension has different clavulanate concentrations than standard suspensions—they cannot be substituted 2.
Ignoring resistance patterns: In communities with >10% penicillin-nonsusceptible S. pneumoniae, consider higher amoxicillin doses in children 6. However, recent adult data suggests standard dosing remains adequate 4, 1.
Clinical Algorithm
Step 1: Confirm ABRS diagnosis
- Symptoms >10 days without improvement, OR
- Double worsening pattern
Step 2: Assess severity and risk factors
- Adults: Standard-dose amoxicillin-clavulanate 875/125 mg BID × 7 days (or consider amoxicillin alone 875 mg BID)
- Children (low-risk): Amoxicillin 45 mg/kg/day divided BID
- Children (high-risk): Amoxicillin-clavulanate 90 mg/kg/day divided BID × 10 days
Step 3: Counsel on adverse effects