Cephalosporins Lecture Notes PDF

Cephalosporins Dr. Sahand K Arif 1  Cephalosporin antibiotics – derived from “cephalosporin C” – obtained from fungus Cephalosporium acremonium Cephalosporin nucleus Consists of dihydrothiazine ring fused to a β–lactam ring 7-aminocephalosporanic acid 7-aminoce...

Cephalosporins Dr. Sahand K Arif 1  Cephalosporin antibiotics – derived from “cephalosporin C” – obtained from fungus Cephalosporium acremonium Cephalosporin nucleus Consists of dihydrothiazine ring fused to a β–lactam ring 7-aminocephalosporanic acid 7-aminocephalosporanic acid has been modified by addition of different side chains to create a whole family of cephalosporin antibiotics. these have been conventionally divided into 5 generations 2  Mechanism of action All cephalosporins are bactericidal. MOA same as penicillin- Inhibit cell wall synthesis in a manner similar to penicillins Bind to different proteins than those which bind penicillin. PBP-1 &PBP-3. This explains difference in spectrum, potency & lack of resistance. Inhibition of transpeptidation Imperfect cell wall Osmotic drive Activation of autolysin enzymes Lysis of bacteria BACTERICIDAL 3  Cephalosporins have several characteristics in common: – All have cross-allergenicity with penicillins. – Generally, more resistant to beta-lactamases than penicillins are. Side effects and toxicity of Cephalosporin Fever, and anaphylaxis. Flushing and rash. Seizures. Clostridium difficile‐associated diarrhea (CDAD). Nausea, vomiting and stomach cramps. 4 CLASSIFICATION 5 6 7 8 9 10 11 12 13 14 15