Cefdinir Dosing Calculation for 100-Pound Patient
For a 100-pound (45.4 kg) pediatric patient, the appropriate dose of cefdinir 250mg/5mL suspension is 9 mL twice daily (BID) or 18 mL once daily, depending on the indication. 1
Weight-Based Dosing Algorithm
Step 1: Convert Weight and Calculate Total Daily Dose
- Patient weight: 100 pounds = 45.4 kg
- Standard pediatric dosing: 14 mg/kg/day (total daily dose) 1
- Calculated total daily dose: 45.4 kg × 14 mg/kg = 635.6 mg/day
- Maximum allowable dose: 600 mg/day 1
- Therefore, this patient receives the maximum dose of 600 mg/day 1
Step 2: Determine Volume Based on Concentration
Using the 250mg/5mL suspension:
- 600 mg ÷ 250 mg = 2.4 (number of 250mg units needed)
- 2.4 × 5 mL = 12 mL total daily volume
Step 3: Select Dosing Frequency Based on Indication
For most infections (otitis media, sinusitis, pharyngitis):
- 7 mg/kg every 12 hours OR 14 mg/kg every 24 hours 1
- BID dosing: 6 mL (300 mg) twice daily 1
- Once-daily dosing: 12 mL (600 mg) once daily 1
For uncomplicated skin and skin structure infections:
- Must use BID dosing only: 6 mL (300 mg) twice daily 1
- Once-daily dosing has not been studied for skin infections 1
Practical Dosing Chart Reference
According to the FDA-approved dosing chart for patients ≥43 kg using 250mg/5mL suspension: 1
- BID regimen: 6 mL every 12 hours
- Once-daily regimen: 12 mL every 24 hours
Critical Considerations
Duration of Therapy
- Acute otitis media: 5-10 days (BID) or 10 days (once daily) 1
- Acute sinusitis: 10 days 1
- Pharyngitis/tonsillitis: 5-10 days (BID) or 10 days (once daily) 1
- Skin infections: 10 days (BID only) 1
Administration Guidelines
- May be given without regard to meals 1
- Shake suspension well before each dose 1
- Suspension stable for 10 days after reconstitution at room temperature 1
Common Pitfall to Avoid
Do not exceed 600 mg/day total dose, even though weight-based calculation (14 mg/kg × 45.4 kg = 635.6 mg) suggests a higher dose. The FDA label explicitly caps the maximum daily dose at 600 mg. 1
Special Population Adjustments
If this patient has renal insufficiency (creatinine clearance <30 mL/min/1.73 m²):
- Reduce to 7 mg/kg (up to 300 mg) once daily 1
- For this patient: 6 mL (300 mg) once daily