What is the adult dose for Augmentin (amoxicillin/clavulanate)?

Adult Dosing for Augmentin (Amoxicillin/Clavulanate)

For most adult infections, use 500 mg/125 mg three times daily or 875 mg/125 mg twice daily, with the 875 mg formulation preferred for respiratory tract infections. 1, 2

Standard Dosing Regimens

Mild-to-Moderate Infections

• 500 mg amoxicillin/125 mg clavulanate three times daily provides adequate coverage for uncomplicated urinary tract infections, skin/soft tissue infections, and mild respiratory infections 1, 2
• This regimen delivers consistent drug levels throughout the day for pathogens with moderate susceptibility 1

Respiratory Tract Infections (Preferred)

• 875 mg amoxicillin/125 mg clavulanate twice daily is specifically recommended for acute bacterial rhinosinusitis, community-acquired pneumonia, and acute exacerbations of chronic bronchitis 1, 2
• The twice-daily dosing improves compliance while maintaining therapeutic drug levels 2

High-Dose Regimen for Drug-Resistant Pathogens

Use 2000 mg amoxicillin/125 mg clavulanate twice daily when treating patients at risk for drug-resistant Streptococcus pneumoniae, including those with: 1, 3

• Recent antibiotic use within 4-6 weeks 1
• Immunodeficiency or immunosuppressive therapy 1
• Frequent daycare exposure or healthcare contact 1
• Geographic areas with >25% penicillin-resistant S. pneumoniae 2

This high-dose formulation uses a pharmacokinetically enhanced delivery system that overcomes resistance through increased drug exposure while maintaining the same clavulanate dose to minimize gastrointestinal side effects 3, 4

Duration of Treatment by Indication

• Acute bacterial rhinosinusitis: 5-7 days 5, 2
• Community-acquired pneumonia: At least 7 days, with duration based on clinical response 3, 2
• Acute exacerbations of chronic bronchitis: At least 7 days 3, 2
• Uncomplicated urinary tract infections: 5 days 6
• Streptococcal pharyngitis (chronic carriers): 10 days 5

Critical Dosing Considerations and Common Pitfalls

Do NOT Substitute Formulations

• Never substitute two 250 mg tablets for one 500 mg tablet, as this doubles the clavulanate dose (250 mg vs 125 mg) and significantly increases gastrointestinal side effects, particularly diarrhea 1, 5
• The clavulanate component is fixed at 125 mg per dose in standard formulations regardless of amoxicillin content 2

Renal Dose Adjustments Required

For patients with severe renal impairment: 1

• GFR 10-30 mL/min: 250-500 mg every 12 hours
• GFR <10 mL/min: 250-500 mg every 24 hours

Treatment Failure Protocol

If no clinical improvement occurs after 72 hours: 1, 2

• Switch to a respiratory fluoroquinolone (levofloxacin 750 mg daily or moxifloxacin 400 mg daily) 1
• Consider alternative diagnoses including viral infection, resistant pathogens, or complications 1
• Reevaluate for abscess formation, empyema, or non-bacterial etiology 1

Formulation-Specific Guidance

Liquid Formulations

• Liquid formulations should not be used interchangeably with tablets without calculating equivalent amoxicillin doses, as the clavulanate ratios differ between formulations 1
• The pharmacokinetically enhanced tablet (Augmentin XR 2000/125 mg) cannot be crushed or substituted with liquid 4

Completion of Therapy

• Complete the full prescribed course even if symptoms improve early to prevent treatment failure and resistance development 1, 2
• Early discontinuation increases risk of relapse and selection of resistant organisms 4