Co-Amoxiclav Dosing Recommendations
For adults with respiratory infections, use co-amoxiclav 875/125 mg twice daily for standard infections, or escalate to 2000/125 mg twice daily when antibiotic resistance is likely or for severe infections. 1
Adult Dosing Regimens
Standard Dosing
- 500/125 mg three times daily provides adequate coverage for mild-to-moderate infections including skin/soft tissue infections and uncomplicated respiratory infections 2, 3
- 875/125 mg twice daily is the preferred regimen for respiratory tract infections (acute bacterial rhinosinusitis, community-acquired pneumonia, acute exacerbations of chronic bronchitis) due to improved compliance and less diarrhea compared to three-times-daily dosing 1, 2, 4
High-Dose Regimen
- 2000/125 mg twice daily achieves adequate serum concentrations to eradicate penicillin-resistant Streptococcus pneumoniae with amoxicillin MICs up to 4-8 mg/L 1, 5
- Use high-dose when any of these risk factors are present: 1, 6
- Recent antibiotic use (within 4-6 weeks)
- Close contact with healthcare environment
- Previous antibiotic therapy failure
- High community prevalence of resistant bacteria (>10% penicillin-resistant S. pneumoniae)
- Moderate to severe infection (frontal/sphenoidal sinusitis)
- Comorbidities (diabetes, chronic heart/lung/liver/kidney disease)
- Immunocompromised status
- Age >65 years
- Smoking or close contact with daycare children
Intravenous Dosing
- 1.2 g (1000/200 mg) every 8 hours IV for severe infections including complicated intra-abdominal infections, severe respiratory infections, and severe skin/soft tissue infections 2, 7
- Switch from IV to oral formulation as soon as clinically appropriate 1
Pediatric Dosing
Infants <12 Weeks
- 30 mg/kg/day (amoxicillin component) divided every 12 hours due to incompletely developed renal function 3
- Use 125/31.25 mg per 5 mL oral suspension (experience with 200/28.5 mg formulation is limited in this age group) 3
Children ≥12 Weeks
Standard Dosing:
- 45 mg/kg/day every 12 hours OR 40 mg/kg/day every 8 hours for more severe infections (otitis media, sinusitis, lower respiratory tract infections) 1, 3
- 25 mg/kg/day every 12 hours OR 20 mg/kg/day every 8 hours for less severe infections 1, 3
- The every-12-hour regimen is preferred as it causes significantly less diarrhea 3
High-Dose Regimen:
- 80-90 mg/kg/day (amoxicillin component) with 6.4 mg/kg/day (clavulanate) divided into 2 doses for: 1, 6
- Age <2 years
- Daycare attendance
- Recent antibiotic treatment (within 30 days)
- Concurrent conjunctivitis (otitis-conjunctivitis syndrome)
- Areas with high prevalence of penicillin-resistant S. pneumoniae (>10%)
- Pneumonia not responding to amoxicillin alone
- Maximum amoxicillin dose: 4000 mg/day 6
- The 14:1 ratio (amoxicillin:clavulanate) in high-dose formulations causes less diarrhea than other preparations 6
Children ≥40 kg
- Dose according to adult recommendations 3
Duration of Therapy
- Acute bacterial rhinosinusitis: 5-7 days in adults 1, 2; 10-14 days in children 1, 6
- Community-acquired pneumonia: 7-10 days (may extend to 14 days based on clinical response) 1, 6
- Uncomplicated urinary tract infections: 3-7 days 1
- Acute otitis media: 10 days 3
- Intra-abdominal infections: 4-7 days with adequate source control 2
Critical Dosing Considerations
Avoid these common pitfalls:
- Do NOT substitute two 250 mg tablets for one 500 mg tablet—this results in excessive clavulanate dosing 2
- The 250/125 mg tablet and 250/62.5 mg chewable tablet are NOT interchangeable due to different clavulanate content 3
- Do NOT use the 250/125 mg tablet until the child weighs at least 40 kg 3
- Evaluate clinical response within 48-72 hours; if no improvement after 72 hours, consider changing antibiotics or reevaluating the diagnosis 1, 6
In areas with >10% penicillin-resistant S. pneumoniae prevalence, ALWAYS use high-dose formulations (2000/125 mg twice daily for adults or 90 mg/kg/day for children) with predicted clinical efficacy of 90-92% 1, 6