What cefdinir concentration should be administered to a 6‑year‑old child weighing 55 lb?

Cefdinir Dosing for a 55-Pound 6-Year-Old

For a 6-year-old child weighing 55 pounds (25 kg), administer cefdinir 175 mg (7 mL of the 125 mg/5 mL suspension) every 12 hours, or 350 mg (14 mL of the 125 mg/5 mL suspension) once daily. 1

Weight-Based Dosing Calculation

• Weight conversion: 55 pounds = 25 kg 1
• Standard pediatric dosing: The FDA-approved regimen for children 6 months through 12 years is either 7 mg/kg every 12 hours OR 14 mg/kg every 24 hours, with a maximum daily dose of 600 mg 1
• Calculated dose for this patient:
  • Twice-daily option: 7 mg/kg × 25 kg = 175 mg every 12 hours (total 350 mg/day) 1
  • Once-daily option: 14 mg/kg × 25 kg = 350 mg every 24 hours 1

Practical Suspension Dosing

Using the 125 mg/5 mL concentration (most appropriate for this weight):

• Twice-daily: 7 mL every 12 hours 1
• Once-daily: 14 mL every 24 hours 1

Using the 250 mg/5 mL concentration (alternative):

• Twice-daily: 3.5 mL every 12 hours 1
• Once-daily: 7 mL every 24 hours 1

Dosing Frequency Selection

• Once-daily dosing is as effective as twice-daily dosing for acute otitis media, sinusitis, and pharyngitis/tonsillitis when given for 10 days 1
• Twice-daily dosing is required for uncomplicated skin and skin structure infections, as once-daily dosing has not been studied for these indications 1
• Once-daily dosing improves adherence and is preferred when clinically appropriate 2

Treatment Duration by Indication

• Acute bacterial otitis media: 5–10 days (twice-daily) or 10 days (once-daily) 1
• Acute maxillary sinusitis: 10 days (either regimen) 1
• Pharyngitis/tonsillitis: 5–10 days (twice-daily) or 10 days (once-daily) 1
• Skin infections: 10 days (twice-daily only) 1

Clinical Context and Positioning

• Cefdinir is an alternative agent, not first-line therapy, for most pediatric infections 3
• The Infectious Diseases Society of America positions cefdinir alongside cefixime, cefpodoxime, and ceftibuten as alternatives specifically for β-lactamase-producing Haemophilus influenzae when amoxicillin-clavulanate cannot be used 4, 3
• High-dose amoxicillin (90 mg/kg/day) remains superior for resistant pneumococcal infections and is the preferred first-line agent for community-acquired pneumonia 3

Administration Instructions

• Cefdinir may be administered without regard to meals 1
• Shake the suspension well before each dose 1
• Store at room temperature (25°C/77°F) in a tightly closed container 1
• Discard any unused suspension after 10 days 1

Common Pitfalls to Avoid

• Do not use once-daily dosing for skin infections—the FDA label explicitly states this has not been studied and twice-daily dosing is required 1
• Do not exceed 600 mg total daily dose regardless of weight 1
• Avoid using cefdinir as first-line empiric therapy for community-acquired pneumonia when high-dose amoxicillin is appropriate 3
• Diarrhea occurs in approximately 8–12.5% of pediatric patients; counsel families that this is usually mild and does not require discontinuation 5, 6