Amoxicillin-Clavulanate (Amox-Clav) Dosing
For adults with respiratory infections, use 875 mg/125 mg twice daily for standard cases, or escalate to 2000 mg/125 mg twice daily (high-dose) when antibiotic resistance is likely—including recent antibiotic use within 4-6 weeks, treatment failure, age >65, or comorbidities. 1, 2
Adult Dosing Regimens
Standard Dose
- 500 mg/125 mg three times daily OR 875 mg/125 mg twice daily for mild-to-moderate infections 3, 4
- The 875 mg twice daily formulation is specifically recommended for respiratory tract infections (sinusitis, community-acquired pneumonia, acute bronchitis exacerbations) 4
- Duration: 5-7 days for uncomplicated acute bacterial rhinosinusitis in adults 1, 4
High-Dose Regimen (When Resistance is Likely)
- 2000 mg/125 mg twice daily for adults with risk factors 1, 2
- This high-dose achieves adequate serum concentrations to eradicate penicillin-resistant Streptococcus pneumoniae with MICs up to 4-8 mg/L 1
Risk factors requiring high-dose therapy include: 1, 2
- Antibiotic use in previous 4-6 weeks
- Previous treatment failure
- Age >65 years
- Comorbidities (diabetes, chronic heart/lung/liver/kidney disease)
- Immunocompromised status
- Moderate-to-severe infections (frontal/sphenoidal sinusitis)
- High community prevalence of resistant bacteria (>10% penicillin-resistant S. pneumoniae)
- Close contact with daycare centers or healthcare environments
Alternative Dosing for Specific Indications
- Animal/human bites: 875 mg/125 mg twice daily 4
- Skin/soft tissue infections: 875 mg/125 mg twice daily 4
- Intravenous (severe infections): 1.2 g IV every 8 hours 4
Pediatric Dosing
Standard Dose (Children ≥12 weeks)
- 45 mg/kg/day divided every 12 hours for more severe infections (otitis media, sinusitis, lower respiratory tract infections) 3, 1
- 25 mg/kg/day divided every 12 hours for less severe infections 3, 1
- Alternative: 40 mg/kg/day every 8 hours (more severe) or 20 mg/kg/day every 8 hours (less severe) 3
High-Dose Pediatric Regimen
- 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in two divided doses 1, 2
- Maximum amoxicillin dose: 4000 mg/day 2
Indications for high-dose pediatric therapy include: 1, 2
- Age <2 years
- Daycare attendance
- Recent antibiotic use (within 30 days)
- Concurrent conjunctivitis (otitis-conjunctivitis syndrome)
- Areas with high prevalence of penicillin-resistant S. pneumoniae (>10%)
- Treatment failure with standard-dose amoxicillin
Duration in Children
- 10-14 days for acute bacterial rhinosinusitis (longer than adults) 1, 2
- 10 days for acute otitis media 3
- 5 days for non-severe pneumonia 2
Neonates and Infants <12 weeks
- 30 mg/kg/day divided every 12 hours (based on amoxicillin component) 3
- Use 125 mg/5 mL oral suspension (experience with 200 mg/5 mL formulation is limited in this age group) 3
Critical Dosing Considerations
Common pitfalls to avoid: 3
- Never substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet—both contain 125 mg clavulanate, resulting in excessive clavulanate dosing 3
- Do not interchange 250 mg/125 mg tablets with 250 mg/62.5 mg chewable tablets—they contain different amounts of clavulanate 3
- Children weighing ≥40 kg should be dosed according to adult recommendations 3
Administration tips: 3
- Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal intolerance 3
- The twice-daily regimen (every 12 hours) is associated with significantly less diarrhea than three-times-daily dosing 3, 5
- The 14:1 ratio of amoxicillin to clavulanate in high-dose pediatric formulations causes less diarrhea than other preparations 1
Monitoring and reassessment: 1, 2
- Evaluate clinical response within 48-72 hours of initiating therapy 1
- If no improvement after 72 hours, consider changing antibiotics or reevaluating diagnosis with cultures, CT, or endoscopy 2
Special Populations
Penicillin-allergic patients: 2