Cefprozil Dosing for an 8.94kg Pediatric Patient with Amoxicillin Allergy
For an 8.94kg child with a known amoxicillin allergy, administer cefprozil 30 mg/kg/day divided into two doses (approximately 134 mg per dose or 13.4 mL of 125 mg/5mL suspension twice daily), provided the amoxicillin allergy is not an anaphylactic or Type I hypersensitivity reaction. 1, 2
Critical Allergy Assessment Required
Before prescribing cefprozil, you must determine the type of penicillin allergy:
For non-anaphylactic reactions (e.g., rash without respiratory compromise, delayed-onset rash), cefprozil is an appropriate alternative as cross-reactivity between penicillins and second-generation cephalosporins is low (approximately 1-3%). 3
For Type I hypersensitivity or anaphylactic reactions to amoxicillin (e.g., angioedema, bronchospasm, anaphylaxis within 1 hour of administration), cefprozil is contraindicated due to potential cross-reactivity with β-lactam antibiotics. 3, 4
If the patient has a serious β-lactam allergy, alternative non-β-lactam antibiotics such as azithromycin, clarithromycin, or clindamycin should be used instead. 3
Weight-Based Dosing Calculation
Standard dosing regimen:
- Total daily dose: 30 mg/kg/day divided into 2 doses 1, 2, 5
- For 8.94kg patient: 8.94 kg × 30 mg/kg/day = 268.2 mg/day
- Per dose: 134 mg twice daily (every 12 hours) 1, 2
Practical suspension dosing:
Indication-Specific Considerations
The dosing remains consistent across most pediatric indications:
- Acute otitis media: 30 mg/kg/day divided every 12 hours for 10 days 2, 5
- Pharyngitis/tonsillitis: 30 mg/kg/day divided every 12 hours for 10 days 6
- Lower respiratory tract infections: 30 mg/kg/day divided every 12 hours for 10 days 7
- Skin and soft tissue infections: 30 mg/kg/day divided every 12 hours for 10 days 8
Clinical Efficacy and Evidence
Cefprozil has demonstrated superior or equivalent efficacy compared to other β-lactams:
In acute otitis media, cefprozil 30 mg/kg/day showed an 8.3% failure rate compared to 22.5% with amoxicillin/clavulanate (p=0.05), with significantly fewer gastrointestinal side effects. 2
Clinical cure rates of 87-89% have been documented in pediatric populations, comparable to high-dose amoxicillin/clavulanate. 5
Bacteriological eradication rates of 82-100% against common respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 8, 7
Important Safety Considerations
Twice-daily dosing improves adherence compared to three or four times daily regimens with other antibiotics. 2, 5
Lower incidence of diarrhea (9%) compared to amoxicillin/clavulanate (19%, p=0.021). 5
Monitor for treatment failure at 48-72 hours; lack of clinical improvement warrants reevaluation and consideration of alternative therapy. 3
Complete the full 10-day course even if symptoms improve earlier to prevent treatment failure and bacterial resistance. 3, 2
Common Pitfalls to Avoid
Never assume all penicillin allergies are the same - always clarify the type and severity of the reaction before prescribing any β-lactam antibiotic. 3
Do not use cefprozil for MRSA coverage - it is inactive against methicillin-resistant staphylococci. 1, 8
Avoid underdosing - always use actual body weight in kilograms for accurate dose calculations and document the weight on every prescription. 4
Cefprozil is ineffective against most strains of Enterobacter, Pseudomonas, Serratia, and the Bacteroides fragilis group. 1