What is the starting dose of Augmentin (amoxicillin/clavulanate) for an adult patient?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: November 17, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Starting Dose of Augmentin for Adults

For most adult patients, start with Augmentin 500 mg/125 mg every 12 hours for mild-to-moderate infections, or 875 mg/125 mg every 12 hours for respiratory tract infections and more severe infections. 1

Standard Dosing Algorithm

For Mild-to-Moderate Infections

  • Start with 500 mg amoxicillin/125 mg clavulanate every 12 hours for uncomplicated skin/soft tissue infections, uncomplicated urinary tract infections, and mild respiratory infections 2, 3, 1
  • Alternative regimen: 250 mg/125 mg every 8 hours, though the every-12-hour regimen is preferred due to significantly less diarrhea 1

For Respiratory Tract Infections and More Severe Infections

  • Start with 875 mg/125 mg every 12 hours for acute bacterial rhinosinusitis, community-acquired pneumonia, and acute exacerbations of chronic bronchitis 2, 3, 1
  • This higher dose is specifically recommended by the Infectious Diseases Society of America for respiratory infections 2
  • Alternative regimen: 500 mg/125 mg every 8 hours 1

For Drug-Resistant Pathogens

  • Use 2000 mg/125 mg twice daily when treating patients at risk for drug-resistant Streptococcus pneumoniae, such as those with recent antibiotic use within 4-6 weeks, immunodeficiency, or frequent daycare exposure 4
  • The Infectious Diseases Society of America specifically recommends this high-dose regimen for moderate disease or recent antibiotic exposure 4

Critical Dosing Considerations

Administration Timing

  • Take at the start of a meal to enhance absorption of clavulanate and minimize gastrointestinal intolerance 1
  • May be taken without regard to meals, but starting with food is preferred 1

Common Pitfalls to Avoid

  • Never substitute two 250 mg/125 mg tablets for one 500 mg/125 mg tablet because both contain the same amount of clavulanic acid (125 mg), resulting in excessive clavulanate dosing and increased gastrointestinal side effects 2, 4, 1
  • The 250 mg/125 mg tablet and 250 mg/62.5 mg chewable tablet are not interchangeable due to different clavulanate content 1

Duration of Treatment

  • For acute bacterial rhinosinusitis: 5-7 days 2, 3
  • For streptococcal infections: 10 days 2
  • For community-acquired pneumonia: duration based on clinical response 3
  • For acute exacerbations of chronic bronchitis: at least 7 days 3

When to Reassess or Switch Therapy

  • If no clinical improvement occurs after 72 hours, switch to a respiratory fluoroquinolone (levofloxacin or moxifloxacin) or consider alternative diagnoses 4
  • The American Academy of Otolaryngology-Head and Neck Surgery recommends reevaluating for complications or non-bacterial etiology if initial therapy fails 4

Renal Dosing Adjustments

  • For severe renal impairment (GFR <30 mL/min): reduce to 250-500 mg every 12 hours for GFR 10-30 mL/min, or 250-500 mg every 24 hours for GFR <10 mL/min 4

References

Guideline

Amoxiclav Dosing Guidelines for Adults

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Augmentin Adult Dosages for Infections

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Guideline

Augmentin Liquid Dosing for Adults

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.