Amoxicillin-Clavulanate Dosing for Adult Ear Infections
For adults with ear infections (acute otitis media or acute bacterial rhinosinusitis), the standard dose is 875 mg amoxicillin/125 mg clavulanate twice daily, or for severe infections and those with risk factors for resistant organisms, use the high-dose formulation of 2000 mg amoxicillin/125 mg clavulanate twice daily for 5-7 days. 1, 2
Standard Dosing Regimen
- The FDA-approved dose for respiratory tract infections in adults is 875 mg/125 mg every 12 hours 2
- Alternative dosing is 500 mg/125 mg every 8 hours (three times daily) 1
- Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects 2
High-Dose Regimen Indications
Use the high-dose formulation (2000 mg/125 mg twice daily) if any of the following risk factors are present: 1
- Recent antibiotic use within the past 4-6 weeks
- Moderate to severe infection
- Geographic area with high prevalence (>10%) of penicillin-resistant Streptococcus pneumoniae
- Age over 65 years
- Immunocompromised status
- Comorbidities (diabetes, heart disease, lung disease)
- Smoker or exposure to secondhand smoke
- Failed previous antibiotic therapy
- History of recurrent ear infections
Treatment Duration
- 5-7 days is the recommended duration for uncomplicated acute bacterial rhinosinusitis in adults, which is as effective as 10-day courses 1
- Continue treatment for 7 days after symptom resolution to ensure complete eradication 3
- Total course typically ranges from 10-14 days for complete resolution 3
Clinical Efficacy Data
The high-dose formulation demonstrates superior outcomes:
- 90-92% predicted clinical efficacy for high-dose amoxicillin-clavulanate (2000 mg/125 mg or 4000 mg/250 mg daily) versus 83-88% for standard-dose amoxicillin 3
- Successfully treated 96% (24/25) of penicillin-resistant S. pneumoniae infections in clinical trials 4
- The enhanced formulation achieves adequate tissue concentrations to overcome resistant organisms 1
Reassessment Protocol
If no improvement or worsening occurs after 72 hours: 1
- Switch to a respiratory fluoroquinolone (levofloxacin or moxifloxacin)
- Consider alternative diagnosis
- Obtain cultures if not already done
- Consider imaging (CT scan) for complicated sinusitis
Renal Dosing Adjustment
- Patients with glomerular filtration rate <30 mL/min should NOT receive the 875 mg dose 2
- Dose reduction required for severe renal impairment 2
Common Pitfall to Avoid
Do not use standard-dose amoxicillin-clavulanate when risk factors for resistant organisms are present, as this leads to treatment failure rates of 20-25% and promotes antimicrobial resistance 3, 1. The high-dose formulation is specifically designed to overcome penicillin-resistant S. pneumoniae and beta-lactamase-producing organisms 1.