What is the recommended dosage and usage of cefdinir (Cefdinir) for patients with bacterial infections, such as community-acquired pneumonia, acute bacterial sinusitis, or uncomplicated skin infections, considering factors like renal function and potential allergy to cephalosporins (Cephalosporins) or penicillins (Penicillins)?

Cefdinir Dosing and Usage for Bacterial Infections

Standard Adult Dosing

For acute bacterial sinusitis, community-acquired pneumonia, and uncomplicated skin infections in adults, cefdinir 300 mg twice daily for 10 days is the FDA-approved regimen, though 600 mg once daily for 10 days is equally effective for respiratory infections. 1

• Acute maxillary sinusitis: 300 mg every 12 hours OR 600 mg every 24 hours for 10 days 1
• Community-acquired pneumonia: 300 mg every 12 hours for 10 days 1, 2
• Uncomplicated skin infections: 300 mg every 12 hours for 10 days (once-daily dosing has not been studied for skin infections) 1

Pediatric Dosing (Age 6 Months Through 12 Years)

The total daily pediatric dose is 14 mg/kg, up to a maximum of 600 mg per day, administered either as 7 mg/kg every 12 hours or 14 mg/kg once daily for 10 days. 1

• Acute bacterial sinusitis: 7 mg/kg every 12 hours OR 14 mg/kg every 24 hours for 10 days 1
• Skin infections: 7 mg/kg every 12 hours for 10 days (must use twice-daily dosing) 1
• Children weighing ≥43 kg should receive the maximum adult dose of 600 mg daily 1

Position in Treatment Algorithm for Sinusitis

Cefdinir is recommended as an alternative first-line option for patients with penicillin allergy, NOT as primary first-line therapy. 3

• Amoxicillin or high-dose amoxicillin-clavulanate remains the preferred first-line treatment for acute bacterial sinusitis 3
• For penicillin-allergic patients, cefdinir provides comparable activity against S. pneumoniae to second-generation cephalosporins (cefuroxime axetil, cefpodoxime proxetil), but has lower activity against H. influenzae than cefpodoxime 4
• Cefdinir demonstrates 70-85% antimicrobial activity against H. influenzae based on pharmacokinetic/pharmacodynamic breakpoints, compared to 95-100% for cefpodoxime 4

Renal Dose Adjustments

For patients with creatinine clearance <30 mL/min, reduce the dose to 300 mg (or 7 mg/kg in pediatrics) once daily. 1

• Cefdinir is not appreciably metabolized and is eliminated principally via renal excretion 4
• For hemodialysis patients: Give 300 mg (or 7 mg/kg) every other day, with an additional 300 mg (or 7 mg/kg) dose at the conclusion of each hemodialysis session 1

Allergy Considerations

Cefdinir can be safely used in patients with non-Type I (non-anaphylactic) penicillin allergy, as cross-reactivity risk with third-generation cephalosporins is negligible. 3

• For documented Type I penicillin hypersensitivity (anaphylaxis), cefdinir remains an acceptable option, though respiratory fluoroquinolones may be preferred for severe infections 3
• Absolute contraindication: Known cephalosporin hypersensitivity 1
• Cefdinir should NOT be used in patients allergic to cephalexin if they had a severe immediate-type reaction, though dissimilar side chains make cross-reactivity unlikely 3

Clinical Efficacy Against Key Pathogens

Cefdinir provides good coverage against S. pneumoniae (including penicillin-susceptible strains) and moderate coverage against H. influenzae, but has limitations against drug-resistant S. pneumoniae. 4

• Activity against S. pneumoniae: Comparable to cefuroxime axetil and cefpodoxime proxetil 4
• Activity against H. influenzae: Similar to cefuroxime axetil but lower than cefpodoxime proxetil 4
• Activity against M. catarrhalis: 78-96% efficacy 4
• Cefdinir is stable to hydrolysis by 13 common beta-lactamases, providing good activity against beta-lactamase-producing strains of H. influenzae and M. catarrhalis 5, 2

Administration and Tolerability

Cefdinir may be administered without regard to meals, and the suspension formulation is very well accepted among children due to superior taste compared to other oral cephalosporins. 4, 2

• After mixing, suspension can be stored at room temperature (25°C/77°F) for 10 days in a tightly closed container 1
• Shake suspension well before each administration 1
• The most common adverse event is diarrhea, occurring at rates generally similar to or slightly higher than comparator agents 5, 2

Critical Pitfalls to Avoid

Do not use cefdinir as first-line monotherapy when high-dose amoxicillin-clavulanate is appropriate, as cefdinir has inferior activity against drug-resistant S. pneumoniae and H. influenzae compared to optimal first-line agents. 4, 3

• Cefdinir is NOT appropriate for frontal, ethmoidal, or sphenoidal sinusitis—reserve respiratory fluoroquinolones for these anatomic locations due to risk of serious complications 3
• Reassess at 72 hours (pediatrics) or 3-5 days (adults): If no improvement, switch to high-dose amoxicillin-clavulanate or a respiratory fluoroquinolone 3
• Complete the full 10-day course even after symptoms improve to prevent relapse 3
• Do not prescribe cefdinir for viral rhinosinusitis lasting <10 days unless severe symptoms are present (fever ≥39°C with purulent discharge for ≥3 consecutive days) 3