Benzyl Penicillin

Class

β-lactam Penicillin

Dose

1.2g (IV) q6h

Mechanism

Cell Wall Inhibitor

MoA

Inhibits cell wall (peptidoglycan) synthesis by binding to penicillin binding proteins and preventing cell wall completion.  Cell lysis follows.

Time v Conc

Time > MIC

Post Dose Effect

Short

SPectrum

Covers

Doesnt

  • G+ves
  • Staph Aureus
  • Most Gram -ves

Indications

  • Mild CAP (with Doxycycline)

PK

A

Not acidically stable – given IV

D

60% PPB          Vd 0.3L/kg

M

Minimally metabolized by liver

E

Renally excreted (dose reduced in severe renal impairment)

AE

  • Allergy/Anaphylaxis
  • Acute Interstitial Nephritis
  • Seizures (high dose)
  • C Diff, Pseudomembranous colitis

Resistance

b-lactamase producing bacteria

Monitoring

  • Renal fn
  • LFTs