cefalosporine

Cephalosporins, known in some languages as cefalosporine, are a class of beta-lactam antibiotics derived from the mold Acremonium. They kill bacteria by inhibiting cell wall synthesis through binding to penicillin-binding proteins, producing time-dependent bactericidal activity. Over time, cephalosporins have been developed into several generations with progressively broader Gram-negative coverage and varying activity against anaerobes and resistant organisms.

Generations form a practical classification. First-generation agents (examples: cephalexin, cefazolin) have strong activity against Gram-positive cocci and limited Gram-negative activity. Second-generation drugs (eg, cefuroxime, cefoxitin, cefotetan) broaden Gram-negative coverage and add some anaerobic activity. Third-generation agents (cefotaxime, ceftriaxone, ceftazidime) offer enhanced Gram-negative activity and better central nervous system penetration, with ceftazidime providing greater antipseudomonal coverage. Fourth-generation cephalosporins (cefepime) provide broad Gram-positive and Gram-negative activity, including Pseudomonas. Fifth-generation agents (ceftaroline and related drugs) extend activity against MRSA and certain resistant Gram-positive pathogens while retaining Gram-negative activity.

Clinical use spans skin and soft tissue infections, pneumonias, urinary tract infections, intra-abdominal infections, and meningitis in selected cases. Choice depends on the agent’s spectrum, route of administration, and patient factors. Common adverse effects include hypersensitivity reactions, gastrointestinal symptoms, and a risk of Clostridioides difficile infection. Some agents can cause disulfiram-like reactions (notably cefotetan) and, rarely, seizures in settings of renal impairment. Resistance arises mainly through beta-lactamase production and alterations of target PBPs, underscoring the importance of antimicrobial stewardship.