Classification of Cephalosporins

Classification

Cephalosporins are classified on the basis of their chemical structure, clinical pharmacology, antibacterial spectrum, or penicillinase resistance.

a.            Orally administered: cephalexin, cephradine, and cefaclor

b.           Parentrally administered: cephalothin, cephapirin, cephacetrile, and cefazedone. These agents are sensitivity to β-lactamase

c.            Resistant to β-lactamase and parentrally administered: cefuroxime, cefamandole, cefoxitin

d.           Metabolically unstable: cephalothin and cephapirin

Clinically used cephalosporins

I. First-generation cephalosporins

These drugs have the highest activity against gram-positive bacteria and the lowest activity against gramnegative bacteria (Table 4.1)

II. Second-generation cephalosporins

These drugs are more active against gram-negative bacteria and less active against gram-positive bacteria than first-generation members (Table 4.2).

III. Third-generation cephalosporins

These drugs are less active than first-generation drugs against gram-positive organisms, but have a muchexpanded spectrum of activity against gram-negative organisms (Table 4.3).

Moxalactam

IV. Fourth-generation cephalosporins

Cefepime and cefpirome are new fourth-generation parenteral cephalosporins with a spectrum of activity which makes them suitable for the treatment of infections caused by a wide variety of bacteria (Table 4.4).

V. Micellaneous

i. Cefaparole

ii. Cefoperazone