Kefalosporins

Kefalosporins are a class of β-lactam antibiotics derived from the fungus Acremonium (formerly Cephalosporium). They are structurally related to penicillins and function by inhibiting bacterial cell wall synthesis, leading to bacterial cell death. Due to their broad-spectrum activity, kefalosporins are widely used to treat various bacterial infections.

Kefalosporins are commonly categorized into generations based on their spectrum of activity. First-generation agents, such as cefazolin and cephalexin, primarily target Gram-positive bacteria and are effective against skin and soft tissue infections. Second-generation drugs, like cefuroxime, exhibit increased activity against certain Gram-negative bacteria. Third-generation agents, including ceftriaxone and ceftazidime, have enhanced activity against Gram-negative organisms and better ability to penetrate the cerebrospinal fluid, making them suitable for central nervous system infections. Fourth and fifth-generation kefalosporins, such as cefepime and ceftaroline, offer expanded activity against resistant bacteria, including methicillin-resistant Staphylococcus aureus (MRSA).

Kefalosporins are generally administered via injection or oral forms, depending on the specific drug. Common side effects include allergic reactions, gastrointestinal disturbances, and, less frequently, hematologic abnormalities. Resistance to kefalosporins can develop through bacterial production of β-lactamases, enzymes that inactivate the antibiotic.

Their broad efficacy and relative safety have made kefalosporins a cornerstone in antimicrobial therapy. However, appropriate use is essential to mitigate resistance development and preserve their effectiveness. The choice of a specific kefalosporin depends on the infection site, bacterial susceptibility, and patient-specific factors.