What is the recommended dose of Augmentin (amoxicillin/clavulanate) for an adult patient with a suspected bacterial infection and potentially impaired renal function?

Adult Dosing of Augmentin (Amoxicillin/Clavulanate)

For adults with normal renal function, the standard dose of Augmentin is 500 mg/125 mg every 12 hours or 250 mg/125 mg every 8 hours for mild-to-moderate infections, while more severe infections (particularly respiratory tract infections) require 875 mg/125 mg every 12 hours or 500 mg/125 mg every 8 hours. 1

Standard Dosing Regimens

For Mild-to-Moderate Infections

• 500 mg/125 mg tablet every 12 hours is the usual adult dose 1
• Alternatively, 250 mg/125 mg tablet every 8 hours can be used 1

For Severe Infections and Respiratory Tract Infections

• 875 mg/125 mg tablet every 12 hours is preferred for more severe infections 1
• This regimen is associated with significantly less severe diarrhea compared to 500 mg/125 mg every 8 hours 1
• Alternatively, 500 mg/125 mg every 8 hours can be used 1

Critical Dosing Considerations

Renal Impairment

Dose adjustment is essential in patients with impaired renal function, as amoxicillin elimination is affected by renal dysfunction. 1

• Patients with renal impairment should be dosed with caution 1
• The standard dosing recommendations assume normal renal and hepatic function 1
• For patients with chronic renal insufficiency (glomerular filtration rate 55-70 mL/min), Augmentin has been used successfully at 375 mg three times daily for 6-12 days 2

Hepatic Impairment

• Hepatically impaired patients should be dosed with caution 1
• Hepatic function must be monitored at regular intervals 1

High-Dose Formulations for Resistant Pathogens

For drug-resistant Streptococcus pneumoniae and beta-lactamase-producing organisms, a pharmacokinetically enhanced formulation of 2000 mg/125 mg twice daily (Augmentin XR) is available for adults. 3

• This high-dose formulation is specifically designed for respiratory tract infections caused by drug-resistant pathogens 3
• It provides coverage against S. pneumoniae with reduced penicillin susceptibility and beta-lactamase-producing H. influenzae and M. catarrhalis 3

Duration of Therapy

Treatment duration typically ranges from 7-10 days depending on the infection type and severity. 2, 4

• Urinary tract infections: 6-12 days 2
• Respiratory tract infections: 7-10 days 2
• Acute orchiepididymitis: 7-10 days 2

Important Formulation Warnings

The 250 mg/125 mg tablet and the 250 mg/62.5 mg chewable tablet are NOT interchangeable due to different clavulanic acid content. 1

• The 250 mg/125 mg tablet contains 125 mg of clavulanic acid 1
• The 250 mg/62.5 mg chewable tablet contains only 62.5 mg of clavulanic acid 1
• The 250 mg/125 mg tablet should not be used until the patient weighs at least 40 kg 1

Common Pitfalls to Avoid

• Do not assume all Augmentin formulations are equivalent - the ratio of amoxicillin to clavulanic acid varies significantly between formulations 1
• Do not use standard dosing in renal impairment - dose adjustment is mandatory to prevent toxicity 1, 2
• Do not ignore hepatic function - regular monitoring is required in hepatically impaired patients 1
• Do not underdose severe infections - use the 875 mg/125 mg twice daily regimen rather than lower doses to optimize outcomes and minimize resistance 1, 3