Cefazolin (Ancef) Dosing for a 10-Year-Old, 100-Pound Male with Facial Laceration
For a 10-year-old, 100-pound (45 kg) male with a facial laceration, the recommended dose of cefazolin (Ancef) is 33 mg/kg/dose IV every 8 hours, which equals approximately 1.5 grams per dose. 1
Weight-Based Dosing Calculation
- The FDA-approved pediatric dosage for cefazolin is 25-50 mg/kg/day divided into 3-4 equal doses for most mild to moderately severe infections 2
- For skin and soft tissue infections (including lacerations), the Infectious Diseases Society of America recommends 33 mg/kg/dose every 8 hours for children 1
- For a 45 kg child (100 pounds), this equals approximately 1,485 mg per dose, which can be rounded to 1.5 grams per dose 2
Administration Considerations
- Cefazolin can be administered intravenously as a direct (bolus) injection over 3-5 minutes 2
- For IV administration, reconstitute with Sterile Water for Injection and further dilute with approximately 5 mL Sterile Water for Injection 2
- Alternatively, it can be administered as an intermittent infusion by diluting in 50-100 mL of compatible IV solution 2
Duration of Therapy
- For uncomplicated skin and soft tissue infections such as facial lacerations, a short course of therapy is typically sufficient 1
- For surgical prophylaxis in clean-contaminated wounds (which may apply to facial lacerations), a single preoperative dose may be sufficient, with additional doses for 24 hours postoperatively if needed 2
Special Considerations
- No dosage adjustment is necessary for this patient as he has no reported renal impairment 2
- Cefazolin is the preferred agent for skin and soft tissue infections caused by methicillin-susceptible Staphylococcus aureus (MSSA), which is a common pathogen in traumatic skin injuries 1
Common Pitfalls to Avoid
- Do not underdose cefazolin in children with significant weight - this 10-year-old at 45 kg should receive dosing closer to adult recommendations than typical pediatric dosing 2
- Avoid using alternative antibiotics due to concerns about penicillin allergy (if present) without confirming the nature of the allergy, as cefazolin has minimal cross-reactivity with penicillin in most cases 3, 4
- Do not extend antibiotic therapy unnecessarily beyond what is clinically indicated, as this can contribute to antimicrobial resistance 1
This dosing recommendation prioritizes adequate coverage for potential pathogens while maintaining safety for a child of this age and weight.