[Evaluation of the so-called basic cephalosporins using the serum bactericidal test].

Area of Science:

• Pharmacology
• Microbiology
• Clinical Medicine

Context:

• Intravenous antibiotic administration is a common clinical practice.
• Understanding the pharmacokinetic and pharmacodynamic profiles of antibiotics is crucial for effective treatment.
• Serum bactericidal activity (SBA) is a key indicator of antibiotic efficacy against specific pathogens.

Purpose:

• To compare the serum bactericidal activity (SBA) of cefotiam, cefuroxime, and cefazolin after intravenous administration.
• To evaluate the efficacy of these antibiotics against a panel of common clinical isolates, including Gram-positive and Gram-negative bacteria.
• To assess the duration of SBA at different time points post-administration.

Summary:

• Six volunteers received intravenous cefotiam (1g and 2g), cefuroxime (1.5g), or cefazolin (2g).
• Serum samples were tested for bactericidal activity against 136 clinical isolates, including Staphylococcus aureus, Escherichia coli, and Haemophilus influenzae, at one and four hours post-administration.
• Four hours post-administration, cefazolin exhibited high activity against Staphylococcus aureus (96% killed at 1:8 dilution), whereas cefotiam showed the highest SBA titers against Haemophilus influenzae and superior activity against Gram-negative bacteria (E. coli, K. pneumoniae, P. mirabilis) compared to cefuroxime and cefazolin.

Impact:

• Cefotiam demonstrates potent activity against Gram-negative pathogens, suggesting its utility in treating infections caused by these bacteria.
• Cefazolin remains a strong option for Staphylococcus aureus infections, showing sustained bactericidal activity.
• These findings provide valuable data for antibiotic selection and dosing strategies in clinical practice, optimizing treatment outcomes.