What is the appropriate cefditoren (cefditoren pivoxil) dosing for an adult with normal renal function for acute bacterial sinusitis, otitis media, streptococcal pharyngitis, or skin/soft‑tissue infection, and what first‑line alternatives are available if the patient cannot tolerate cefditoren or the pathogen is resistant?

Cefditoren Pivoxil Dosing and Clinical Use

Standard Adult Dosing for Approved Indications

For acute bacterial sinusitis, pharyngitis/tonsillitis, and uncomplicated skin/soft-tissue infections, prescribe cefditoren pivoxil 200 mg orally twice daily for 10 days. 1, 2

• For acute exacerbations of chronic bronchitis or community-acquired pneumonia, the dose is 400 mg orally twice daily for 10 days. 1, 2
• Cefditoren must be taken with food to enhance absorption; peak plasma concentrations occur approximately 2–3 hours after administration. 2
• The terminal half-life is 0.8–1.3 hours, and the drug is eliminated almost entirely via renal clearance of unchanged compound. 2

Antimicrobial Spectrum and Clinical Positioning

• Cefditoren demonstrates excellent activity against Streptococcus pneumoniae (including penicillin-resistant strains), Haemophilus influenzae, Moraxella catarrhalis, methicillin-susceptible Staphylococcus aureus, and Streptococcus pyogenes. 3, 1, 4
• The drug is stable to hydrolysis by many common β-lactamases, making it effective against β-lactamase-producing H. influenzae and M. catarrhalis. 3, 1, 2
• Cefditoren has no activity against atypical respiratory pathogens (Chlamydia pneumoniae, Mycoplasma pneumoniae, Legionella species), Pseudomonas aeruginosa, or Bacteroides fragilis. 4

First-Line Alternatives When Cefditoren Is Not Appropriate

For Acute Bacterial Sinusitis

• Amoxicillin-clavulanate 875 mg/125 mg twice daily for 5–10 days is the preferred first-line agent for adults with normal renal function, providing 90–92% predicted clinical efficacy against the major sinusitis pathogens. 5
• For patients with non-severe penicillin allergy, second- or third-generation cephalosporins (cefuroxime-axetil, cefpodoxime-proxetil, cefdinir) are appropriate alternatives for 10 days; cross-reactivity is negligible. 5
• For patients with severe (Type I/anaphylactic) penicillin allergy, respiratory fluoroquinolones—levofloxacin 500 mg once daily for 10–14 days or moxifloxacin 400 mg once daily for 10 days—provide 90–92% predicted efficacy. 5

For Streptococcal Pharyngitis

• Penicillin V 500 mg orally twice daily for 10 days or amoxicillin 500 mg twice daily for 10 days remains the gold standard for group A β-hemolytic streptococcal pharyngitis due to universal susceptibility, narrow spectrum, low cost, and proven efficacy in preventing acute rheumatic fever. 5
• For penicillin-allergic patients with non-severe allergy, first-generation cephalosporins (cephalexin 500 mg twice daily for 10 days) are appropriate. 5
• For patients with severe penicillin allergy, azithromycin 500 mg on day 1, then 250 mg daily for days 2–5, or clarithromycin 250 mg twice daily for 10 days are acceptable alternatives, though macrolide resistance rates are 20–25% in some regions. 5

For Uncomplicated Skin/Soft-Tissue Infections

• Cephalexin 500 mg orally four times daily for 7–10 days or dicloxacillin 500 mg four times daily for 7–10 days are first-line agents for cellulitis or impetigo caused by methicillin-susceptible S. aureus or Streptococcus pyogenes. 5
• For patients with penicillin allergy, clindamycin 300–450 mg orally three times daily for 7–10 days provides excellent gram-positive coverage. 5

When Cefditoren Is Preferred Over Alternatives

• Cefditoren is particularly useful when there is concern about S. pneumoniae with decreased penicillin susceptibility or β-lactamase-mediated resistance among community-acquired respiratory pathogens. 3, 1
• In clinical trials, cefditoren demonstrated good clinical and bacteriological efficacy in acute maxillary sinusitis, pharyngitis/tonsillitis, and uncomplicated skin infections, with favorable tolerability. 3, 1

Pathogen Resistance Considerations

• Avoid macrolides (azithromycin, clarithromycin) as first-line therapy for sinusitis due to 20–25% resistance rates in S. pneumoniae and H. influenzae. 5
• Trimethoprim-sulfamethoxazole should not be used for sinusitis because resistance is ≈50% in S. pneumoniae and ≈27% in H. influenzae. 5
• First-generation cephalosporins (cephalexin) are inadequate for sinusitis because ≈50% of H. influenzae strains produce β-lactamase. 5

Pediatric Considerations

• In Japanese pediatric studies, cefditoren pivoxil granules at 3 mg/kg three times daily (total daily dose 9 mg/kg) achieved a 97.3% overall clinical efficacy rate and 90.4% bacteriological eradication rate in various infections. 6
• The drug demonstrated dose-dependent pharmacokinetics with peak serum concentrations at 2–3 hours and urinary recovery rates of 17–19% in the first 8 hours. 6
• Diarrhea was the primary side effect (4.2% incidence), but no serious adverse events were noted in pediatric patients. 6

Safety Profile and Adverse Effects

• The most common side effects are diarrhea, nausea, vomiting, headache, and dyspepsia. 4
• Cefditoren was generally well tolerated in clinical trials across all approved indications. 3, 1

Critical Pitfalls to Avoid

• Do not use cefditoren for infections requiring coverage of atypical pathogens (Mycoplasma, Chlamydia, Legionella); add a macrolide or fluoroquinolone if atypical coverage is needed. 4
• Ensure the patient takes cefditoren with food to optimize absorption and therapeutic efficacy. 2
• Adjust dosing in renal impairment because the drug is eliminated almost entirely via renal clearance. 2