When should Ceftin (cefuroxime axetil) be preferred over Keflex (cephalexin) for treating infections?

When to Prefer Ceftin (Cefuroxime Axetil) Over Keflex (Cephalexin)

Ceftin should be preferred over Keflex when treating infections caused by beta-lactamase-producing organisms—particularly Haemophilus influenzae and Moraxella catarrhalis—or when broader gram-negative coverage is required for respiratory tract infections.

Key Clinical Scenarios Favoring Ceftin

Respiratory Tract Infections with Beta-Lactamase Producers

• Cefuroxime axetil demonstrates superior activity against beta-lactamase-producing H. influenzae and M. catarrhalis compared to first-generation cephalosporins, making it the preferred choice for acute bacterial rhinosinusitis, acute otitis media, and lower respiratory tract infections when these pathogens are suspected 1.
• Cefuroxime is the most active cephalosporin against beta-lactamase-producing H. influenzae, a critical advantage in respiratory infections where this organism is common 2.
• The activity of cefuroxime axetil against S. pneumoniae is similar to cefpodoxime and cefdinir, while being less active than cefpodoxime against H. influenzae but still clinically effective 1.

Acute Bacterial Rhinosinusitis

• For patients who have failed high-dose amoxicillin or amoxicillin/clavulanate (or cannot tolerate them), cefuroxime axetil 500 mg twice daily for 10 days is an appropriate second-line option 1.
• Cefuroxime provides broader coverage than first-generation cephalosporins for the typical sinus pathogens including penicillin-resistant S. pneumoniae 1.

Lyme Disease (Early Localized or Disseminated)

• Cefuroxime axetil 500 mg twice daily for 14–21 days is recommended as a first-line alternative to doxycycline or amoxicillin for early Lyme disease with erythema migrans 1.
• This indication is unique to cefuroxime among cephalosporins and represents a clear advantage over cephalexin 1.

Skin and Soft Tissue Infections

• Cefuroxime axetil achieved a 97% satisfactory clinical outcome in skin/skin structure infections, significantly superior to cephalexin's 89% (p=0.047) 3.
• Bacteriological eradication was also superior: 96% with cefuroxime versus 85% with cephalexin (p=0.026) 3.

When Keflex Should Be Preferred Instead

Streptococcal Pharyngitis

• First-generation cephalosporins like cephalexin are preferred over cefuroxime for Group A streptococcal pharyngitis in penicillin-allergic patients (non-anaphylactic) because they have a narrower spectrum, lower cost, and strong high-quality evidence 1, 4.
• Cephalexin 500 mg twice daily for 10 days is the recommended regimen 1, 4.

Uncomplicated Lower Urinary Tract Infections

• Cephalexin 500 mg twice or thrice daily is highly effective for uncomplicated UTIs caused by non-ESBL Enterobacteriaceae, with early bacteriological and clinical cure rates comparable to traditional first-line agents 5.
• Cephalexin is more cost-effective and has a narrower spectrum than cefuroxime for this indication 5.

Simple Skin Infections (Non-Complicated)

• For straightforward cellulitis or impetigo where S. aureus or S. pyogenes are the primary pathogens without beta-lactamase concerns, cephalexin is adequate and more economical 4.

Comparative Spectrum and Activity

Gram-Positive Coverage

• Both agents have similar activity against methicillin-sensitive S. aureus and streptococci, though first-generation cephalosporins are generally slightly more active against gram-positive cocci 2.
• Cefuroxime is less active against gram-positive cocci than first-generation cephalosporins but compensates with superior gram-negative coverage 2.

Gram-Negative Coverage

• Cefuroxime has significantly broader gram-negative activity, including H. influenzae, M. catarrhalis, E. coli, Klebsiella, and Proteus mirabilis, while cephalexin has limited gram-negative spectrum 6, 7, 2.
• This broader coverage makes cefuroxime appropriate for empirical treatment of community-acquired infections where gram-negative pathogens are likely 7.

Pharmacokinetic Considerations

• Cefuroxime axetil has 68% bioavailability after oral administration with food, achieving peak plasma concentrations of 7.9 mg/L after a 500 mg dose 6.
• Both agents are well-tolerated with similar adverse event profiles, predominantly mild gastrointestinal disturbances 6, 7, 3.
• Cefuroxime demonstrates good tissue penetration into bronchial mucosa, tonsils, and bronchial secretions, making it particularly suitable for respiratory infections 6.

Common Pitfalls to Avoid

• Do not use cefuroxime as first-line for streptococcal pharyngitis—first-generation cephalosporins are preferred due to narrower spectrum and lower cost 1, 4.
• Do not prescribe broad-spectrum cephalosporins like cefuroxime when narrow-spectrum first-generation agents are appropriate, as this unnecessarily promotes antibiotic-resistant flora 1, 4.
• First-generation cephalosporins like cephalexin are ineffective for Lyme disease—only cefuroxime axetil among oral cephalosporins is recommended 1.
• For urologic prophylaxis, cefuroxime is listed as a second-generation option but cephalexin remains appropriate for many procedures 1.

Practical Dosing Summary

Cefuroxime Axetil:

• Respiratory infections: 500 mg PO twice daily for 10 days 1
• Lyme disease: 500 mg PO twice daily for 14–21 days 1
• Skin infections: 250–500 mg PO twice daily for 10 days 6, 3

Cephalexin:

• Streptococcal pharyngitis: 500 mg PO twice daily for 10 days 1, 4
• UTI: 500 mg PO 2–3 times daily for 3–7 days 5
• Skin infections: 500 mg PO twice daily for 10 days 3