A Class of its Own

Question 1

What is the mechanism of action for Nitroimidazole drugs like Metronidazole?

Answer 1

Bactericidal: Pro-drugs converted to active metabolites which then damage DNA and proteins via reduction reactions

Question 2

What is the spectrum of activity for Metronidazole?

Answer 2

Anaerobes and protozoa (Clostridioides difficile, Gardnerella vaginalis, H. pylori, Trichomonas, Giardia, Amebiasis)

Question 3

In which formulations is Metronidazole available?

Answer 3

Oral, intravenous (IV), topical, vaginal

Question 4

What are the common dosing instructions for Metronidazole?

Answer 4

500 mg orally twice a day for 7 days

Question 5

What are the common side effects of Metronidazole?

Answer 5

GI effects such as nausea, dysgeusia (metallic taste), headache; CNS effects such as vertigo, insomnia, and rare but possibly severe rash

Question 6

What are the drug interactions associated with Metronidazole?

Answer 6

Alcohol can cause an Antabuse-like reaction; potentiates anticoagulant effects of warfarin; increases plasma levels of of lithium = lithium toxicity