Metronidazole

Class

Nitroimidazole

Dose

500mg q8h

Mechanism

Bactericidal

MoA

Taken up by anaerobic bacteria

Inhibits DNA synthesis by breaking DNA strands

Time v Concentration

Concentration dependent killing

Spectrum​

Covers

Doesn't Cover

Anaerobes including C diff

H Pylori (3 therapy)

Protozoans

Most Gram positives & Gram negatives

Indications

Anaerobic infections

C diff (2nd line; but is the only IV agent available for C diff as IV Vancomycin does not penetrate the lumen)

PK

A

100% OBA

D

CSF penetration (unlike clinda)

M

Hepatic metabolism

E

70% excreted as metabolites

20% unchanged in urine

10% in feces

 

Half life may be prolonged w liver impairment

A/E

Nausea

Diarrhoea

Metallic taste

Peripheral neuropathy (long term use)

Disulfram effect w ETOH

Prolonged QT

Monitoring

LFTs