What is the recommended dosing for an adult who can only take liquid Augmentin (amoxicillin/clavulanate)?

Augmentin Liquid Dosing for Adults

For adults requiring liquid Augmentin, use 500 mg amoxicillin/125 mg clavulanate (10 mL of the 250 mg/5 mL suspension) three times daily for mild-to-moderate infections, or 875 mg amoxicillin/125 mg clavulanate (17.5 mL of the 250 mg/5 mL suspension) twice daily for respiratory tract infections. 1, 2

Standard Liquid Dosing Regimens

Mild-to-Moderate Infections

• 500 mg/125 mg three times daily (every 8 hours) provides adequate coverage for most mild-to-moderate infections 1, 2
• Using the 250 mg/5 mL suspension: administer 10 mL three times daily 3
• This regimen is appropriate for skin/soft tissue infections, uncomplicated urinary tract infections, and mild respiratory infections 2

Respiratory Tract Infections

• 875 mg/125 mg twice daily (every 12 hours) is preferred for acute bacterial rhinosinusitis, community-acquired pneumonia, and acute exacerbations of chronic bronchitis 1, 2
• Using the 250 mg/5 mL suspension: administer 17.5 mL twice daily 3
• Duration for uncomplicated acute bacterial rhinosinusitis is 5-7 days 4

High-Dose Regimen for Resistant Pathogens

When treating infections in patients at risk for drug-resistant Streptococcus pneumoniae (recent antibiotic use, immunodeficiency, frequent daycare exposure):

• Use 2000 mg amoxicillin/125 mg clavulanate twice daily 4
• Using the 250 mg/5 mL suspension: administer 40 mL twice daily 3
• This high-dose regimen is recommended by IDSA guidelines for adults with moderate disease or recent antibiotic exposure within 4-6 weeks 4

Critical Dosing Considerations

Formulation Warnings

• Never substitute two 250 mg doses for one 500 mg dose, as this results in excessive clavulanate dosing and increased gastrointestinal side effects 1
• The clavulanate component remains fixed at 125 mg per dose regardless of amoxicillin content 2

Renal Impairment

• Reduce the dose in patients with severe renal impairment (GFR <30 mL/min) 3
• For GFR 10-30 mL/min: 250-500 mg every 12 hours
• For GFR <10 mL/min: 250-500 mg every 24 hours

Treatment Failure

• If no clinical improvement occurs after 72 hours, switch to a respiratory fluoroquinolone (levofloxacin, moxifloxacin) or consider alternative diagnoses 4, 2
• Reevaluate the patient for complications or non-bacterial etiology 4

Common Pitfalls to Avoid

• Do not use liquid formulations interchangeably with tablets without calculating equivalent amoxicillin doses, as the clavulanate ratios differ between formulations 1
• Complete the full course even if symptoms improve early to prevent treatment failure and resistance development 1
• Monitor for gastrointestinal side effects (diarrhea, nausea), which are the most common adverse reactions occurring in >1% of patients 3
• Screen for Clostridioides difficile infection if diarrhea develops during or after treatment 3