What is the typical concentration and dosing of Augmentin (amoxicillin and clavulanic acid) for infections?

Augmentin (Amoxicillin/Clavulanic Acid) Concentration and Dosing for Infections

For adult infections, the standard concentration of Augmentin is 875 mg amoxicillin/125 mg clavulanic acid given twice daily, or 500 mg amoxicillin/125 mg clavulanic acid given three times daily, depending on the severity of infection.

Adult Dosing Regimens

Standard Dosing Options:

• Mild to Moderate Infections:

  • 500 mg/125 mg every 8 hours (three times daily)
  • 875 mg/125 mg every 12 hours (twice daily) 1

• Severe Infections and Respiratory Tract Infections:

  • 875 mg/125 mg every 12 hours
  • 500 mg/125 mg every 8 hours 1

Special Considerations for Specific Infections:

• Skin and Soft Tissue Infections:

  • 875/125 mg twice daily 2

• Respiratory Tract Infections:

  • 875/125 mg twice daily (preferred for better compliance) 2

Pediatric Dosing

• Children <40 kg:

  • 25 mg/kg/day of the amoxicillin component in 2 divided doses for mild infections
  • 45 mg/kg/day in 2 divided doses for severe infections 2

• Children ≥40 kg:

  • Follow adult dosing recommendations 1

• High-dose formulation for resistant organisms:

  • 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in two divided doses 2, 3

Important Administration Guidelines

• Take at the start of a meal to minimize gastrointestinal intolerance and enhance clavulanate absorption 1, 4
• Twice-daily dosing has similar efficacy to three-times-daily dosing with fewer gastrointestinal side effects 5
• When the clavulanate dose exceeds approximately 10 mg/kg/day, diarrhea can become problematic 2

Dosing in Special Populations

Renal Impairment:

• GFR 10-30 mL/min: 500 mg/125 mg or 250 mg/125 mg every 12 hours
• GFR <10 mL/min: 500 mg/125 mg or 250 mg/125 mg every 24 hours
• Hemodialysis patients: Additional dose both during and at the end of dialysis 1
• Severe impairment (GFR <30 mL/min): Should NOT receive 875 mg/125 mg formulation 1

Clinical Pharmacology

• Peak serum levels of amoxicillin reach approximately 11.23 μg/mL at 2 hours after oral administration of 875/125 mg dose
• Peak serum levels of clavulanic acid reach approximately 2.55 μg/mL at 1 hour 6
• Tissue penetration varies by site, with lung tissue achieving higher concentrations (2.56 μg/g for amoxicillin) compared to other tissues 6

Common Pitfalls to Avoid

1. Formulation confusion: Two 250 mg/125 mg tablets are NOT equivalent to one 500 mg/125 mg tablet due to the same amount of clavulanate (125 mg) in both formulations 1

2. Inadequate dosing for resistant organisms: For suspected penicillin-resistant S. pneumoniae, higher doses of amoxicillin are required 2

3. Gastrointestinal intolerance: Taking without food can increase the risk of GI side effects; twice-daily dosing has fewer GI side effects than three-times-daily dosing 2, 5

4. Inappropriate use in severe renal impairment: The 875 mg formulation should be avoided in patients with GFR <30 mL/min 1

Augmentin remains a valuable broad-spectrum antibiotic with excellent activity against common respiratory and skin/soft tissue pathogens, including beta-lactamase-producing organisms, when dosed appropriately based on infection severity and patient factors.