From WikiMD's Health & Wellness Encyclopedia

Cephalosporins are a large group of antibiotics derived from the mold Acremonium, which was formerly known as Cephalosporium. These antibiotics are structurally and functionally similar to penicillins and are categorized into generations based on their spectrum of antimicrobial activity.

Cephalosporin Cxx

Classification and Structure

Cephalosporins are classified into five generations. Each successive generation has a broader spectrum of activity against gram-negative bacteria. The basic structure of cephalosporins is a four-membered beta-lactam ring, linked to a six-membered dihydrothiazine ring.

Mechanism of Action

Cephalosporins work by disrupting the synthesis of the peptidoglycan layer of bacterial cell walls. They bind to specific penicillin-binding proteins located inside the bacterial cell wall, thereby inhibiting the last step of peptidoglycan synthesis.


Cephalosporins are used in treating a wide array of infections caused by both gram-positive and gram-negative bacteria. These include respiratory tract infections, skin and soft tissue infections, urinary tract infections, sexually transmitted infections, and septicemia among others.

Side Effects and Precautions

While generally well tolerated, side effects may include diarrhea, allergic reactions, and in rare cases, antibiotic-associated colitis. Hypersensitivity reactions in those allergic to penicillin can occur.


Bacterial resistance to cephalosporins has increased, mainly due to the production of beta-lactamase enzymes which cleave the beta-lactam ring rendering the antibiotic ineffective.


See Also


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