Should the co-amoxiclav (amoxicillin/clavulanic acid) dose be increased from 1g?

Co-Amoxiclav Dosing: When to Increase from 1g

No, the standard oral dose of co-amoxiclav should remain 625 mg (500 mg amoxicillin/125 mg clavulanate) three times daily for most respiratory infections in adults, not 1g. The 1.2g intravenous dose is reserved specifically for severe pneumonia requiring parenteral therapy. 1

Standard Oral Dosing for Adults

For hospital-treated, non-severe respiratory infections (including COPD exacerbations and non-severe pneumonia), the recommended oral dose is co-amoxiclav 625 mg three times daily. 1 This provides adequate coverage for the typical pathogens including S. pneumoniae, H. influenzae, M. catarrhalis, and S. aureus. 1

• The 625 mg formulation (500 mg amoxicillin/125 mg clavulanate) has demonstrated clinical success rates of 90.8% in bacterial exacerbations of chronic bronchitis, with eradication rates of 82.2%. 2
• This standard dose is effective for most community-acquired respiratory infections when oral therapy is appropriate. 1

When to Escalate to High-Dose Therapy

High-dose oral co-amoxiclav (2g amoxicillin/125 mg clavulanate twice daily) is indicated only in specific high-risk situations: 1, 3

• Recent antibiotic use within the past 4-6 weeks 3
• Failed previous antibiotic therapy 3
• Moderate to severe disease presentation 3
• Age over 65 years 3
• Immunocompromised status 3
• High local prevalence (>10%) of penicillin-resistant S. pneumoniae 3
• Frontal or sphenoidal sinusitis 3

Intravenous Dosing: The 1.2g Threshold

The 1.2g intravenous dose (1g amoxicillin/200 mg clavulanate) three times daily is reserved exclusively for severe pneumonia requiring parenteral therapy. 1 This is not equivalent to or interchangeable with oral dosing.

• IV therapy is indicated when patients cannot tolerate oral medication or have severe pneumonia with adverse prognostic features. 1
• Switch from IV to oral should occur as soon as clinically appropriate, transitioning to co-amoxiclav 625 mg three times daily orally. 1
• For severe pneumonia, IV co-amoxiclav 1.2g three times daily should be combined with a macrolide (erythromycin 500 mg four times daily IV or clarithromycin 500 mg twice daily IV). 1

Critical Dosing Pitfalls to Avoid

Do not use 1g oral dosing as a standard regimen. The evidence-based oral dose is 625 mg three times daily for standard infections. 1

• In countries with high penicillin-resistant S. pneumoniae prevalence, increase the amoxicillin component to 1g every 8 hours (not co-amoxiclav 1g, but amoxicillin 1g with standard clavulanate). 1
• Research suggests that even standard IV dosing may be insufficient for severe Enterobacteriaceae infections, with some data supporting six times daily dosing rather than the standard four times daily. 4
• Only 65% of hospitalized patients achieved the pharmacodynamic target (40% time above MIC) with standard dosing for bacterial MICs of 8 mg/L. 4

Treatment Duration

For adults with uncomplicated acute bacterial rhinosinusitis, 5-7 days of therapy is sufficient and as effective as 10-14 days. 1, 3 For children, maintain the longer 10-14 day duration. 1

• For COPD exacerbations, maintain treatment for 7-10 days on average. 1
• Reassess patients who fail to improve within 48-72 hours and consider alternative diagnoses or resistant pathogens. 1, 3