What are the indications, dosing regimens, contraindications, and renal dose adjustments for cefdinir?

Cefdinir: Indications, Dosing, Contraindications, and Renal Adjustments

Primary Indications

Cefdinir is indicated for community-acquired respiratory tract infections and uncomplicated skin/skin structure infections, serving as an alternative to amoxicillin in patients with non-Type I penicillin hypersensitivity. 1, 2

Respiratory Tract Infections

• Acute otitis media in pediatric patients, particularly when amoxicillin has failed or the patient has non-Type I penicillin allergy 1
• Acute bacterial rhinosinusitis in adults with mild disease and no recent antibiotic use (past 4-6 weeks) 3, 2
• Community-acquired pneumonia as an alternative oral cephalosporin option, though not preferred over amoxicillin for penicillin-susceptible S. pneumoniae 2, 4
• Acute bacterial exacerbations of chronic bronchitis 4, 5
• Pharyngitis/tonsillitis caused by Streptococcus pyogenes 4, 5

Skin and Soft Tissue Infections

• Uncomplicated skin and skin structure infections caused by S. aureus and S. pyogenes 4, 5, 6

Dosing Regimens

Pediatric Dosing

• Standard dose: 14 mg/kg/day administered either once daily or divided into 2 doses 1, 4
• Treatment duration: 5-10 days depending on the infection 4, 5
• Maximum daily dose should not exceed adult dosing 5

Adult and Adolescent Dosing

• 300 mg twice daily OR 600 mg once daily 4, 7
• Treatment duration: 5-10 days depending on infection type and severity 4, 5

Contraindications and Precautions

Absolute Contraindications

• Type I hypersensitivity reactions to penicillins (anaphylaxis, angioedema) - while cross-reactivity with cephalosporins is low (~0.1%), cefdinir is not recommended for true Type I reactions 1, 2
• Known hypersensitivity to cefdinir or other cephalosporins 5

Drug Interactions

• Avoid coadministration with antacids containing magnesium or aluminum, which significantly impair cefdinir absorption 2

Clinical Limitations

• Inadequate coverage in areas with high drug-resistant S. pneumoniae (DRSP) prevalence - cefdinir lacks clinically significant activity against penicillin-resistant pneumococcal strains 1, 2
• Not recommended for moderate disease with recent antibiotic use (within 4-6 weeks) - prefer respiratory fluoroquinolones or high-dose amoxicillin-clavulanate instead 2

Renal Dose Adjustments

Adults with Renal Impairment

• Creatinine clearance ≥30 mL/min: No adjustment necessary 5
• Creatinine clearance <30 mL/min: Reduce dose to 300 mg once daily 5
• Hemodialysis patients: 300 mg once daily; administer dose after dialysis on dialysis days 5

Pediatric Patients with Renal Impairment

• Creatinine clearance ≥30 mL/min: No adjustment necessary 5
• Creatinine clearance <30 mL/min: Reduce dose to 7 mg/kg once daily (maximum 300 mg/day) 5

Clinical Algorithm for Use

Step 1: Assess Penicillin Allergy Status

• Non-Type I reaction (rash only): Cefdinir is appropriate 1, 2
• Type I reaction (anaphylaxis, angioedema): Avoid cefdinir; use macrolides, fluoroquinolones, or TMP-SMX instead 3

Step 2: Evaluate Recent Antibiotic Exposure

• No antibiotics in past 4-6 weeks: Cefdinir is appropriate for mild disease 3
• Recent antibiotic use: Consider high-dose amoxicillin-clavulanate or respiratory fluoroquinolones instead 2

Step 3: Reassess if No Improvement at 48-72 Hours

• Confirm diagnosis and exclude other causes 1
• Switch to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate) 1
• Alternative: Ceftriaxone 50 mg IM/IV for 3 days 1

Key Clinical Pitfalls

Antimicrobial Spectrum Limitations

• Poor activity against drug-resistant S. pneumoniae - less effective than cefpodoxime against H. influenzae 1, 2
• Not suitable for empiric therapy in high-resistance areas 1

Common Adverse Effects

• Diarrhea is the most common adverse event, occurring more frequently than with comparators like penicillin V, cephalexin, and cefprozil 5, 7
• Discontinuation rates due to adverse events are generally similar to comparators despite higher diarrhea incidence 5

Advantages

• Superior palatability of oral suspension compared to other antimicrobials, improving pediatric compliance 1, 4
• Convenient once- or twice-daily dosing enhances adherence 4, 5
• Stable against common beta-lactamases, retaining activity against beta-lactamase-producing H. influenzae and M. catarrhalis 4, 5