What is the appropriate cefdinir dose for a 14.97 kg child using a suspension of 250 mg per 5 mL, given a history of an immediate anaphylactic reaction to amoxicillin?

Cefdinir Dosing for a 14.97 kg Child with Penicillin Anaphylaxis

For a child weighing 14.97 kg with a history of immediate anaphylactic reaction to amoxicillin, administer cefdinir 7 mg/kg every 12 hours (approximately 3.5 mL of 250 mg/5 mL suspension twice daily), which totals 105 mg per dose or 210 mg daily. 1

Weight-Based Calculation

• The FDA-approved pediatric dosing for cefdinir is 14 mg/kg/day total, which can be administered as either 7 mg/kg every 12 hours (twice daily) or 14 mg/kg once daily 1
• For this 14.97 kg child: 14.97 kg × 7 mg/kg = 104.79 mg per dose (round to 105 mg) 1
• Using the 250 mg/5 mL suspension: 105 mg ÷ 50 mg/mL = 2.1 mL per dose 1
• However, the FDA dosage chart recommends 2.5 mL of 250 mg/5 mL suspension every 12 hours for children in the 9-18 kg weight range, which provides 125 mg per dose 1

Practical Dosing Recommendation

• Administer 2.5 mL of the 250 mg/5 mL suspension every 12 hours (125 mg per dose, 250 mg daily total), as this aligns with the FDA dosage chart and provides slightly higher coverage within the approved range 1
• This dosing is appropriate for acute bacterial otitis media, acute maxillary sinusitis, pharyngitis/tonsillitis (5-10 days), or uncomplicated skin infections (10 days) 1

Critical Considerations for Penicillin-Allergic Patients

• Cephalosporins like cefdinir are appropriate for patients with non-anaphylactic penicillin reactions (e.g., rash), but the question specifically states an immediate anaphylactic reaction to amoxicillin 2
• The cross-reactivity risk between penicillins and cephalosporins in true IgE-mediated anaphylaxis is approximately 1-3%, but cefdinir is generally considered safer than first-generation cephalosporins 2, 3
• Guidelines recommend cefdinir as the preferred cephalosporin for penicillin-intolerant patients due to better palatability and twice-daily dosing 2

Important Caveats

• For true Type I hypersensitivity (anaphylaxis) to amoxicillin, alternative non-β-lactam antibiotics should be strongly considered first, such as azithromycin (12 mg/kg once daily for 5 days) or clarithromycin, depending on the infection type 3, 4
• If cefdinir is used despite anaphylaxis history, administer the first dose under medical observation with epinephrine readily available 2
• Cefdinir provides excellent coverage against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis, making it particularly useful for respiratory infections 2, 5, 6

Duration of Therapy

• Acute otitis media or sinusitis: 5-10 days 1
• Pharyngitis/tonsillitis: 5-10 days (though 10 days preferred for Group A Streptococcus) 1
• Uncomplicated skin infections: 10 days 1

Monitoring and Follow-Up

• Clinical improvement should occur within 48-72 hours; if no improvement, reevaluation is necessary 2, 3
• Watch for signs of allergic reaction, particularly with the first few doses, given the anaphylaxis history 2
• The suspension remains stable for 10 days after reconstitution when stored at room temperature; shake well before each dose 1