cephalosporinok

Cephalosporinok, commonly known in English as cephalosporins, are a class of beta-lactam antibiotics derived from the fungus Acremonium. They share a beta-lactam ring and a dihydrothiazine ring in their chemical structure and act by inhibiting bacterial cell wall synthesis through binding to penicillin-binding proteins. This action causes bactericidal effects, and effectiveness often depends on time above the MIC.

Cephalosporins are traditionally grouped into generations that reflect differences in spectrum and properties. First-generation agents (for example, cefazolin, cephalexin) have strong activity against gram-positive cocci and moderate activity against certain gram-negative rods. Second-generation cephalosporins broaden gram-negative coverage and include cephamycins such as cefotetan and cefoxitin, which have notable anaerobic activity. Third-generation agents (such as ceftriaxone, cefotaxime, ceftazidime) offer greater gram-negative coverage and improved tissue penetration, with some activity against Pseudomonas aeruginosa. Fourth-generation cephalosporins (cefepime) combine broad spectrum with enhanced stability to certain beta-lactamases. Fifth-generation cephalosporins (ceftaroline, ceftobiprole) extend activity to MRSA and certain resistant gram-negatives.

Pharmacokinetics vary: many cephalosporins are given orally or by injection, are predominantly excreted renally, and require dose adjustments in kidney impairment. They are used for a range of infections, including skin and soft tissue infections, pneumonia, urinary tract infections, intra-abdominal infections, and meningitis with selected agents. Some drugs are combined with beta-lactamase inhibitors to counter resistance.

Adverse effects are typically mild but can include hypersensitivity reactions, cross-reactivity with penicillins, gastrointestinal upset, and rare nephrotoxicity or seizures at high doses. Disulfiram-like reactions are associated with certain agents in the cephamycins group.