What is the dosing regimen for Augmentin (amoxicillin/clavulanate)?

Augmentin (Amoxicillin/Clavulanate) Dosing

For adults with mild-to-moderate infections, use 500 mg/125 mg three times daily or 875 mg/125 mg twice daily; for severe infections or when antibiotic resistance is likely, use 2000 mg/125 mg twice daily. 1

Adult Dosing Regimens

Standard Dosing for Mild-to-Moderate Infections

• 500 mg/125 mg three times daily is the standard regimen for mild-to-moderate infections including respiratory tract infections, skin/soft tissue infections, and urinary tract infections 1
• 875 mg/125 mg twice daily is an alternative standard dose specifically recommended for respiratory infections including acute bacterial rhinosinusitis, community-acquired pneumonia, and acute exacerbations of chronic bronchitis 1
• Both formulations provide adequate coverage for most community-acquired infections caused by Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 1

High-Dose Regimen for Resistant Pathogens

• 2000 mg/125 mg twice daily should be used when antibiotic resistance is likely, including recent antibiotic use within 4-6 weeks, healthcare contact, prior treatment failure, or high community prevalence of resistant bacteria 2, 1
• This high-dose formulation achieves adequate serum concentrations to eradicate penicillin-resistant S. pneumoniae with amoxicillin MICs up to 4-8 mg/L 1
• Consider high-dose therapy for moderate-to-severe infections, patients >65 years, immunocompromised status, or comorbid conditions (diabetes, chronic heart/lung/liver/kidney disease) 1

Special Clinical Scenarios

• Animal or human bites: 500 mg/125 mg twice daily 1
• Recurrent streptococcal pharyngitis: 500 mg twice daily for 10 days 1
• Lyme disease with bacterial cellulitis: 500 mg three times daily for 14 days 1
• Intravenous dosing: 1.2 g IV every 8 hours for serious infections including complicated intra-abdominal infections, severe respiratory infections, and severe skin/soft tissue infections 1

Pediatric Dosing

Standard Pediatric Regimens

• For children ≥12 weeks with less severe infections: 25 mg/kg/day every 12 hours or 20 mg/kg/day every 8 hours 3, 4
• For children ≥12 weeks with more severe infections: 45 mg/kg/day every 12 hours or 40 mg/kg/day every 8 hours 3, 4
• For children <12 weeks: Maximum 30 mg/kg/day divided every 12 hours due to incompletely developed renal function 4

High-Dose Pediatric Formulation

• 90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in two divided doses for acute bacterial rhinosinusitis, resistant infections, or persistent/recurrent acute otitis media 2, 3
• This high-dose formulation (14:1 ratio) was specifically developed to address drug-resistant S. pneumoniae while maintaining the same daily clavulanate dose as standard formulations 5

Duration of Therapy

Infection-Specific Duration

• Respiratory tract infections: 7-10 days 1, 3
• Acute bacterial rhinosinusitis (adults): 5-7 days 1
• Acute bacterial rhinosinusitis (children): 10-14 days 3
• Streptococcal infections: Minimum 10 days to prevent acute rheumatic fever 1, 4
• Uncomplicated UTI: 3-7 days 3
• Febrile UTI in infants/children: 7-14 days 2
• Intra-abdominal infections: 4-7 days with adequate source control 1
• Community-acquired pneumonia: 5-7 days if afebrile for 48 hours and clinically stable 1

Critical Treatment Principles

• Continue treatment for a minimum of 48-72 hours beyond clinical improvement or evidence of bacterial eradication 4
• Evaluate clinical response within 48-72 hours of initiating therapy; if no improvement, consider switching to alternative antimicrobial therapy or reevaluating the patient 2, 3

Renal Dosing Adjustments

Adults and Children >40 kg with Renal Impairment

• GFR 10-30 mL/min: 500 mg or 250 mg every 12 hours 4
• GFR <10 mL/min: 500 mg or 250 mg every 24 hours 4
• Hemodialysis: 500 mg or 250 mg every 24 hours, with an additional dose during and at the end of dialysis 4
• Do NOT use the 875 mg dose in patients with GFR <30 mL/min 4

Critical Dosing Considerations and Pitfalls

Common Errors to Avoid

• Never substitute two 250 mg tablets for one 500 mg tablet, as this results in excessive clavulanate dosing and increased gastrointestinal side effects 1
• Avoid underdosing in areas with high penicillin-resistant S. pneumoniae prevalence (>10%); always use high-dose formulations in these regions 1
• Do not use nitrofurantoin for febrile UTIs in infants, as it does not achieve adequate parenchymal or serum concentrations to treat pyelonephritis or urosepsis 2

Administration Guidelines

• Take at the start of a meal to minimize gastrointestinal intolerance 4
• For oral suspension, shake well before using and discard unused portion after 14 days 4
• Switch from IV to oral therapy as soon as clinically appropriate 3

Monitoring and Safety

• Gastrointestinal side effects occur in approximately 9% of patients with three-times-daily regimens 1
• When combining with other nephrotoxic drugs or in patients with renal dysfunction, avoid aminoglycosides to minimize nephrotoxicity risk 1
• Complete the full course of therapy to prevent treatment failure, resistance development, and complications 1