Augmentin (Amoxicillin-Clavulanate) Dosing and Treatment Guidelines
For adults with respiratory tract infections, use 875 mg/125 mg twice daily or 500 mg/125 mg three times daily for standard infections, escalating to 2000 mg/125 mg twice daily for high-risk patients or resistant organisms. 1, 2
Adult Dosing Regimens
Standard Dose
- 500 mg/125 mg every 8 hours OR 875 mg/125 mg every 12 hours for mild to moderate respiratory infections 2
- Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects 2
- Duration: 5-7 days for acute bacterial sinusitis, 7-10 days for community-acquired pneumonia 3
High-Dose Regimen (2000 mg/125 mg twice daily)
Use high-dose formulation when ANY of these risk factors are present: 3, 1
- Recent antibiotic use within 4-6 weeks
- Age >65 years
- Moderate to severe disease presentation
- Geographic area with >10% penicillin-resistant S. pneumoniae
- Recent close contact with treated individuals or daycare exposure
- Failed previous antibiotic therapy
- Smoker or exposure to secondhand smoke
- Immunocompromised status or significant comorbidities
- Frontal or sphenoidal sinusitis
This high-dose formulation achieves 90-92% predicted clinical efficacy against resistant organisms 3
Hospital-Based IV Therapy
- 1.2 g IV three times daily for severe pneumonia requiring hospitalization 1
- Switch to oral formulation (625 mg three times daily) as soon as clinically appropriate 1
Pediatric Dosing Regimens
Standard Dose
- 45 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate, divided into 2 doses for uncomplicated infections 1, 4
High-Dose Regimen (90 mg/kg/day)
Use high-dose (90 mg/kg/day amoxicillin with 6.4 mg/kg/day clavulanate in 2 divided doses) when ANY of these are present: 1, 4
- Age <2 years
- Daycare attendance
- Recent antibiotic use within 30 days
- Incomplete Haemophilus influenzae type b vaccination (<3 injections)
- Geographic area with >10% penicillin-resistant S. pneumoniae
- Concurrent purulent conjunctivitis or acute otitis media
- Moderate to severe illness presentation
Maximum dose: 4000 mg/day of amoxicillin component regardless of weight 1, 4
Age-Based Oral Suspension Dosing
- <1 year: 2.5 ml of 125/31 suspension three times daily 4
- 1-6 years: 5 ml of 125/31 suspension three times daily 4
- 7-12 years: 5 ml of 250/62 suspension three times daily 4
- ≥40 kg: Use adult dosing 2
Duration: 10 days for most pediatric respiratory infections 4
Critical Dosing Considerations
The 14:1 Ratio Advantage
The high-dose formulation provides a 14:1 ratio of amoxicillin to clavulanate, which causes significantly less diarrhea than standard formulations while maintaining superior efficacy against resistant organisms 1, 4
Common Dosing Errors to Avoid
- Never substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet - they contain the same amount of clavulanate (125 mg), making this substitution inappropriate 2
- Verify suspension concentration (125/31 vs 250/62) before calculating volume to prevent dosing errors 4
- Do not use 250 mg/125 mg tablets in children <40 kg due to inappropriate amoxicillin:clavulanate ratio 2
Renal Dosing Adjustments
- GFR 10-30 mL/min: 500 mg/125 mg or 250 mg/125 mg every 12 hours 2
- GFR <10 mL/min: 500 mg/125 mg or 250 mg/125 mg every 24 hours 2
- Hemodialysis: 500 mg/125 mg or 250 mg/125 mg every 24 hours, with additional dose during and after dialysis 2
- Do not use 875 mg/125 mg formulation if GFR <30 mL/min 2
Treatment Failure Management
If no clinical improvement after 72 hours, take these steps: 1
- Switch to respiratory fluoroquinolone (levofloxacin or moxifloxacin) in adults 3
- Consider ceftriaxone 1-2 g IV/IM daily for 5 days if oral therapy fails 1
- Obtain cultures, CT imaging, or endoscopy to reassess diagnosis 1
- Evaluate for atypical pathogens, complications, or alternative diagnoses 4
Specific Infection Types
Community-Acquired Pneumonia (Hospitalized, Non-ICU)
- Aminopenicillin/β-lactamase inhibitor ± macrolide is a recommended first-line option 3
- The newer 2000 mg/125 mg formulation offers advantages for pneumococcal pneumonia with low-level penicillin resistance 3
Acute Bacterial Rhinosinusitis
- Adults: 875 mg/125 mg twice daily for 5-7 days (standard risk) OR 2000 mg/125 mg twice daily for 5-7 days (high risk) 3, 1
- Children: 90 mg/kg/day in 2 doses for 10 days (strongly recommended as first-line) 4
Bronchiectasis Exacerbations
- 625 mg three times daily for 14 days for β-lactamase producing H. influenzae 1
Safety Profile
Adverse effects include diarrhea (3.6%), skin reactions (4.8%), nausea, and vomiting 5, 6. The high-dose 14:1 formulation significantly reduces diarrhea incidence compared to other ratios 1, 4. Monitor hepatic function in patients with hepatic impairment 2.