Core pharmacology

Class Group

ANTIBIOTIC:
CEPHALOSPORIN

Legacy Cicm Level

Level 1

Introduction

1st Generation Cephalosporin

Presentation

Capsules 250, 500mg
Powder for oral suspension

Mechanism of action

Beta lactam ring binds to multiple penicillin binding proteins (carboxy/endo/ transpeptidase) and
prevents crosslinking of bacterial peptidoglycan
inhibits cell wall synthesis
BROADER SPECTRUM

Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested

Configuration: Stability against Betalactamases

Onset Peak Duration

250-500mg QID (BD for
UTI)

Antimicrobial Spectrum

Bacteriocidal

Active against:
- Most GPC (not MRSA, enterococcus, staph epidermidis)
- Some E. Coli, Klebsiella, Proteus
- Oral anaerobes (Except B. Fragilis)

Adverse Effects Toxicity

Generally well tolerated
Hypersensitivity reactions (10% cross reactivity with penicillin allergies), thrombophlebitis, interstitial nephritis, low prothrombin, flushing and headaches with EtOH.

Absorption

Rapid and complete absorption, which is not effected by food.

Protein binding

10% PB

Metabolism

Minimal metabolism

Excretion

90% excreted unchanged in urine

Half-life

Plasma T1/2 = 1hr