Amoxicillin-Clavulanate (Amoxclav) Dosing for Bacterial Infections
For adults with most bacterial infections, the standard dose is amoxicillin-clavulanate 875/125 mg twice daily or 500/125 mg three times daily, while high-dose therapy (2000/125 mg twice daily) is reserved for resistant pathogens or severe respiratory infections. 1, 2, 3
Adult Dosing Regimens
Standard-Dose Therapy
- 875/125 mg twice daily is the preferred formulation for most infections including skin/soft tissue infections, animal/human bites, and uncomplicated respiratory infections 1, 4, 3
- 500/125 mg three times daily is an alternative standard regimen, particularly established for respiratory tract infections and sinusitis 1, 4, 3
- Duration is typically 7-10 days for most infections, though acute bacterial rhinosinusitis requires only 5-7 days 2, 3
High-Dose Therapy (2000/125 mg twice daily)
This formulation should be used for adults with risk factors for resistant pathogens, including: 2, 5, 6
- Recent antibiotic use (within 30 days)
- Failed previous antibiotic therapy
- Close contact with daycare children
- Smoking or exposure to secondhand smoke
- Age over 65 years
- Immunocompromised status
- Moderate to severe infections
- Geographic areas with high prevalence of penicillin-resistant Streptococcus pneumoniae (>10%)
The high-dose formulation achieves serum concentrations sufficient to eradicate S. pneumoniae with amoxicillin MICs up to 4 mg/L, including penicillin-resistant strains 5, 6, 7
Pediatric Dosing (Children ≥3 Months and <40 kg)
Standard-Dose Regimen
- 45 mg/kg/day of amoxicillin component divided into two doses every 12 hours (or 20 mg/kg/day divided every 8 hours for milder infections) 2, 8, 3
- This is appropriate for uncomplicated infections without risk factors 2, 8
High-Dose Regimen
- 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day of clavulanate divided into two doses 2, 8, 9
- Indications for high-dose therapy in children include: 2, 8, 9
- Age under 2 years
- Daycare attendance
- Recent antibiotic treatment (within 30 days)
- Failed initial amoxicillin therapy
- Concurrent conjunctivitis (suggests Moraxella catarrhalis)
- Geographic areas with >10% penicillin-resistant S. pneumoniae
- Moderate to severe infections
The 14:1 ratio formulation (high-dose) causes less diarrhea than other amoxicillin-clavulanate preparations 8, 9
Infants <3 Months
- Maximum dose is 30 mg/kg/day divided every 12 hours due to immature renal function 3
- Minimum treatment duration is 48-72 hours beyond symptom resolution 3
Specific Infection Types
Respiratory Tract Infections
- Community-acquired pneumonia (adults): 875/125 mg twice daily or 500/125 mg three times daily; use 2000/125 mg twice daily for severe disease or resistant pathogens 1, 2
- Acute bacterial sinusitis (adults): 875/125 mg twice daily for 5-7 days; high-dose for risk factors 2, 4
- Acute bacterial sinusitis (children): Standard dose for 10-14 days; high-dose if risk factors present 2
- COPD exacerbations: 875/125 mg twice daily for 14 days 1
Skin and Soft Tissue Infections
- Animal or human bites: 875/125 mg twice daily orally 1
- Coverage includes Pasteurella multocida (animal bites) and Eikenella corrodens (human bites) 1
Renal Impairment Dosing
Dose adjustment is required only for severe renal impairment: 3
- GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours
- GFR <10 mL/min: 500 mg or 250 mg every 24 hours
- Hemodialysis: 500 mg or 250 mg every 24 hours, with additional dose during and after dialysis
- Do NOT use 875 mg dose if GFR <30 mL/min 3
Administration and Monitoring
Key Administration Points
- Take at the start of meals to minimize gastrointestinal intolerance 3
- Oral suspension must be shaken well before each use and refrigerated (preferred but not required) 8, 3
- Reconstituted suspension expires after 14 days 3
Common Pitfalls to Avoid
- Underdosing in children: Always calculate based on actual body weight, not age 8
- Using standard dose when high-dose indicated: This promotes treatment failure and resistance 2, 8
- Incorrect frequency: Inadequate dosing intervals result in subtherapeutic drug levels 8
- Premature discontinuation: Continue for minimum 48-72 hours beyond symptom resolution 3
- Using 875 mg dose in severe renal impairment: Risk of toxicity 3
When to Reassess
- If no improvement after 72 hours, reevaluate diagnosis or consider alternative antibiotics 8
- For Streptococcus pyogenes infections, treat for minimum 10 days to prevent acute rheumatic fever 3