What is the correct dosage for amoxicillin (amoxicillin/clavulanic acid) 875/125mg?

Amoxicillin/Clavulanate 875/125mg Dosing

The correct dose for amoxicillin/clavulanate 875/125mg is one tablet twice daily (every 12 hours), which delivers a total daily dose of 1750mg amoxicillin and 250mg clavulanate. 1

Standard Adult Dosing

• One 875/125mg tablet every 12 hours is the FDA-approved regimen for more severe infections and respiratory tract infections 1
• This formulation is specifically designed for twice-daily dosing and should not be substituted with other strengths 1
• The 875/125mg dose is recommended by the Infectious Diseases Society of America specifically for respiratory infections including acute bacterial rhinosinusitis, community-acquired pneumonia, and acute exacerbations of chronic bronchitis 2

Clinical Context and Rationale

• The 875/125mg twice-daily regimen provides adequate time above the minimum inhibitory concentration (T>MIC) for most common respiratory pathogens 3
• This dose achieves approximately 4g/day of amoxicillin, which meets the "high-dose" threshold defined in treatment guidelines for overcoming penicillin-resistant Streptococcus pneumoniae 3
• The formulation maintains coverage against beta-lactamase-producing organisms (H. influenzae, M. catarrhalis) through the clavulanate component 3

Treatment Duration

• For uncomplicated acute bacterial rhinosinusitis: 5-7 days 2
• For chronic rhinosinusitis or acute exacerbations: 14 days 3
• Duration should be based on the specific infection type and clinical response 2

Administration Guidelines

• Take at the start of meals to enhance clavulanate absorption and minimize gastrointestinal side effects 1
• May be taken without regard to meals, but meal-time administration is preferred for tolerability 1

Critical Dosing Warnings

• Never substitute two 250/125mg tablets for one 500/125mg tablet - this results in excessive clavulanate dosing (250mg vs 125mg) 2, 1
• Do not substitute two 500/125mg tablets for one 875/125mg tablet - the clavulanate content differs and this is not an equivalent substitution 1
• Patients weighing ≥40kg should follow adult dosing recommendations 1

Renal Dosing Adjustments

• No dose adjustment needed unless glomerular filtration rate (GFR) <30 mL/min 1
• GFR <30 mL/min: Do not use the 875/125mg formulation - switch to 500/125mg or 250/125mg formulations 1
• GFR 10-30 mL/min: Use 500/125mg or 250/125mg every 12 hours 1
• GFR <10 mL/min or hemodialysis: Use 500/125mg or 250/125mg every 24 hours, with additional dose during and after dialysis 1

Evidence for Efficacy

• The 875/125mg twice-daily regimen demonstrated clinical success rates of 91-93% in acute exacerbations of chronic bronchitis 4
• This formulation showed 92.3% efficacy against S. pneumoniae in community-acquired pneumonia, including penicillin-resistant strains 5
• Studies comparing 875/125mg twice daily versus 500/125mg three times daily showed comparable clinical outcomes in chronic rhinosinusitis 3

Common Pitfalls to Avoid

• Diarrhea is the most common adverse effect - taking with food reduces this risk 3, 1
• Hepatic monitoring should be performed in patients with hepatic impairment 1
• The 875/125mg formulation should not be used in pediatric patients <40kg 1