Augmentin Dosing for Dog Bite to Eye in Child Under 5 Years
For a child under 5 years with a dog bite to the eye, administer Augmentin at 90 mg/kg/day of the amoxicillin component divided into 2 doses (maximum 4000 mg/day) for 7-10 days, combined with topical moxifloxacin 0.5% ophthalmic solution 1 drop three times daily for 7 days. 1, 2, 3
Systemic Antibiotic Therapy (Augmentin)
Weight-Based Dosing Calculation
- High-dose regimen is mandatory for animal bites due to polymicrobial nature and risk of resistant organisms including beta-lactamase producing Pasteurella multocida, Staphylococcus aureus, and anaerobes 1, 3
- Calculate 90 mg/kg/day of amoxicillin component, divided into 2 doses 2, 3
- For example, a 15 kg child would receive: 15 kg × 90 mg/kg = 1350 mg/day, given as 675 mg twice daily 2, 3
- Maximum single dose is 2000 mg regardless of weight 3
Formulation Selection
- Use the 14:1 ratio formulation (90 mg/6.4 mg per kg per day) which provides adequate amoxicillin while minimizing clavulanate-related diarrhea 3, 4, 5
- This high-dose formulation is specifically designed to overcome beta-lactamase producing organisms common in animal bites 1, 4
Duration and Monitoring
- Treatment duration: 7-10 days for animal bite wounds 1, 2
- Clinical improvement should be evident within 48-72 hours; if no improvement occurs, reevaluate for complications including orbital cellulitis, abscess formation, or resistant organisms 2, 3
- The eye location makes this a high-risk bite requiring aggressive therapy due to proximity to critical structures 1
Topical Ophthalmic Antibiotic Therapy
Recommended Agent and Dosing
- Moxifloxacin 0.5% ophthalmic solution: 1 drop to affected eye three times daily for 7 days 1
- Alternatively, gatifloxacin 0.3% ophthalmic solution: 1 drop every 2 hours while awake (up to 8 times daily) for first 2 days, then 1 drop four times daily for days 3-7 1
Rationale for Fluoroquinolone Selection
- Fluoroquinolones provide excellent coverage against Pasteurella multocida, the most common pathogen in dog bites, as well as Staphylococcus and Streptococcus species 1
- Topical therapy is critical for direct ocular surface protection while systemic antibiotics address deeper tissue involvement 1
Critical Clinical Considerations
High-Risk Features Requiring Immediate Ophthalmology Referral
- Any penetrating injury to the globe 1
- Visual changes or decreased visual acuity 1
- Limitation of extraocular movements suggesting orbital involvement 1
- Significant periorbital swelling or proptosis 1
- Purulent discharge suggesting established infection 1
Common Pitfalls to Avoid
- Never use standard-dose Augmentin (45 mg/kg/day) for animal bites - this fails to achieve adequate concentrations against beta-lactamase producing organisms and promotes resistance 1, 3
- Do not rely on topical antibiotics alone for bite wounds - systemic therapy is mandatory due to deep tissue inoculation 1
- Verify the Augmentin suspension concentration before dispensing (the 600 mg/5 mL formulation provides the 14:1 ratio needed) 3, 4
- Augmentin misses MRSA coverage - if MRSA is suspected based on local epidemiology or patient risk factors, add appropriate anti-MRSA therapy 1
Alternative Regimens for Penicillin Allergy
- For non-anaphylactic penicillin allergy: Cefuroxime 30 mg/kg/day divided twice daily PLUS metronidazole 30 mg/kg/day divided three times daily 1
- For severe/anaphylactic penicillin allergy: Doxycycline 2-4 mg/kg/day divided twice daily (if age ≥8 years) OR clindamycin 30-40 mg/kg/day divided three times daily PLUS trimethoprim-sulfamethoxazole 8-10 mg/kg/day (TMP component) divided twice daily 1