What is the recommended dosing regimen for Augmentin (amoxicillin/clavulanate) in an adult patient with a skin infection and normal renal function, considering potential allergies to penicillin or other beta-lactam antibiotics?

Augmentin Dosing for Skin Infections

For adult patients with skin infections and normal renal function, Augmentin should be dosed at 875 mg/125 mg twice daily for 7-10 days, or alternatively 500 mg three times daily for mild to moderate infections. 1

Standard Adult Dosing Regimens

The IDSA guidelines specifically recommend amoxicillin-clavulanate (Augmentin) 875/125 mg twice daily for human bite wounds and other skin infections where mixed aerobic-anaerobic coverage is needed. 1 This dosing provides adequate coverage against common skin pathogens including:

• Staphylococcus aureus (methicillin-susceptible strains) 1
• Streptococcus pyogenes 1
• Anaerobic bacteria 1
• Pasteurella multocida (animal bites) 1

For surgical site infections with significant systemic response (erythema extending >5 cm from wound edge, fever, or elevated white blood cell count), use 875/125 mg twice daily in conjunction with incision and drainage. 1

Treatment Duration

• Standard duration: 7-10 days for most uncomplicated skin infections 1
• Extend to 7-14 days if systemic signs of infection are present or clinical improvement is delayed 1
• Treatment should continue until infection has clinically improved, not solely based on a predetermined protocol 1

Specific Clinical Scenarios

Non-Purulent Cellulitis

For mild cellulitis without systemic signs, oral therapy with agents covering streptococci is typically sufficient. 1 However, when MSSA coverage is desired or there is penetrating trauma, Augmentin 875/125 mg twice daily provides appropriate coverage. 1

Surgical Site Infections

Augmentin is indicated when the surgical site involves the intestinal or genitourinary tract, or the axilla/perineum where anaerobic coverage is essential. 1 The standard dose remains 875/125 mg twice daily. 1

Animal/Human Bites

Augmentin is the preferred oral agent for bite wounds at 875/125 mg twice daily. 1 This provides coverage against Eikenella species (human bites), Pasteurella multocida (cat/dog bites), staphylococci, streptococci, and anaerobes. 1

Important Limitations and Caveats

Resistance Considerations

• Augmentin does NOT cover MRSA 1
• Some gram-negative rods may be resistant 1
• If MRSA is suspected (injection drug use, known MRSA colonization, purulent infection with systemic toxicity), add vancomycin or use an alternative agent like doxycycline 100 mg twice daily or trimethoprim-sulfamethoxazole 1, 2

Penicillin Allergy

If the patient has a documented penicillin or beta-lactam allergy, Augmentin is contraindicated. 3 Alternative regimens include:

• Doxycycline 100 mg twice daily for 7-14 days (good activity against staphylococci and anaerobes) 1, 4
• Clindamycin 300 mg three times daily (covers staphylococci, streptococci, and anaerobes but misses Pasteurella) 1
• Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily (limited anaerobic coverage) 1

Renal Dosing Adjustments

For patients with renal impairment, dosing must be adjusted based on creatinine clearance, though specific adjustments are not detailed in the skin infection guidelines. 3 Consult the FDA label for precise renal dosing recommendations. 3

Common Pitfalls to Avoid

• Do not use Augmentin monotherapy for suspected MRSA infections - this is a critical error as MRSA prevalence is high in many communities 1
• Do not underdose - the 500 mg three times daily regimen may be inadequate for moderate to severe infections; use 875/125 mg twice daily 1
• Do not continue therapy beyond clinical resolution - prolonged unnecessary antibiotic use increases resistance and adverse effects 1
• Do not forget to drain abscesses - antibiotics alone are insufficient for purulent collections requiring incision and drainage 1

Monitoring and Follow-Up

Patients should show clinical improvement within 48-72 hours. 1 If fever persists or erythema progresses despite appropriate therapy, consider:

• Alternative diagnosis (necrotizing fasciitis, deeper infection) 1
• Resistant organism (obtain cultures) 1
• Inadequate source control (undrained abscess) 1
• Drug allergy or adverse reaction 3