Metronidazole

Question 1

Drug class?

Answer 1

Anaerobic antimicrobial

Question 2

How does it work?

Answer 2

• Bactericidal Abx
• Broken down to toxic compounds within microbes with anaerobic/microaerophillic metabolism
• Toxic compounds kill microbes by interfering with nucleic acid function and synthesis

Spectrum = Anaerobes (clostridia, bacteriodes etc.) and protozoa. Trichomonas, entamoeba histolytica, giardia lamblia, balantidium coli.

Question 3

Indications?

Answer 3

Stuff infected with anaerobes.

Question 4

Contra-indications?

Answer 4

Caution: pregnancy, breastfeeding, hepatic impairment

Question 5

Side-effects?

Answer 5

Common: nausea, vomiting, anorexia, diarrhoea
Rarely: anaphylaxis, drowsiness, headache, dizziness, metallic taste in mouth

Question 6

Possible interactions?

Answer 6

P450 INHIBITOR

• Alcohol: causes disulfiram-like reaction (flushing, adbo pain, hypotension)
• Phenytoin:  plasma conc of phenytoin by inhibiting metabolism
• Warfarin:  anticoagulant effect by inhibiting metabolism