Does Cefuroxime Cover Beta-Lactamase Producing H. influenzae?
Yes, cefuroxime effectively covers beta-lactamase producing Haemophilus influenzae and is specifically recommended for this indication. 1, 2
Guideline-Based Recommendations
Second and third generation cephalosporins, including cefuroxime, are explicitly recommended for treatment of beta-lactamase producing H. influenzae. 1 The Taiwan pneumonia guidelines specifically state that when 25-50% of non-typeable strains produce beta-lactamase, amoxicillin and ampicillin should only be used when susceptibility is known, and a second or third generation cephalosporin is the preferred alternative. 1
FDA-Approved Indications
The FDA label for cefuroxime explicitly lists "Haemophilus influenzae (including ampicillin-resistant strains)" as a covered pathogen for multiple indications including: 2
- Lower respiratory tract infections
- Meningitis
- Septicemia
This ampicillin-resistance designation specifically refers to beta-lactamase producing strains. 2
Mechanism of Beta-Lactamase Stability
Cefuroxime has enhanced stability against beta-lactamases compared to earlier cephalosporins and penicillins. 2, 3 The drug maintains activity in the presence of both penicillinases and cephalosporinases from gram-negative and gram-positive bacteria. 2 This beta-lactamase stability is what allows cefuroxime to effectively treat infections caused by beta-lactamase-producing strains of H. influenzae that are resistant to ampicillin. 4, 3
Clinical Evidence Supporting Efficacy
In clinical trials of lower respiratory tract infections, cefuroxime demonstrated a 90% success rate in bronchopneumonia and 89% success rate in acute exacerbations of chronic bronchitis, conditions where beta-lactamase producing H. influenzae is a common pathogen. 5 The oral formulation (cefuroxime axetil) has demonstrated broad spectrum activity against beta-lactamase positive H. influenzae in multiple clinical studies. 6
Comparative Activity Among Cephalosporins
Among second-generation cephalosporins used for sinusitis and respiratory infections, cefuroxime axetil has enhanced activity against beta-lactamase-producing H. influenzae and M. catarrhalis. 7 However, it is important to note that cefuroxime is less active against M. catarrhalis compared to some third-generation agents like cefpodoxime. 1
Important Clinical Caveat
All antimicrobials tested against H. influenzae exhibit a significant inoculum effect, meaning that higher bacterial loads may require higher drug concentrations for effective killing. 8 This emphasizes the importance of appropriate dosing—the standard regimen is 750 mg every 8 hours intramuscularly or intravenously for serious infections. 5