Pharm - Metronidazole

Question 1

MOA metronidazole

Answer 1

anaerobic pathogenic microorganisms donate electrons to metronidazole –> a highly reactive nitro radical anion is formed –> this ion kills of susceptible organisms via radical-mediated DNA damage

Question 2

describe how metronidazole can switch between active and inactive states and what can affect this

Answer 2

metronidazole loses the added electron to become inactive and can gain it back to become active

high O2 levels reduce likelihood of metronidazole entering back into active form and promote recycling of active radical back into inactive form

Question 3

what is the main mechanism of metronidazole resistance

Answer 3

increasing intracellular level of O2

- ex: impaired O2 scavenging that leads to increased levels of O2

Question 4

what bacteria have shown resistance to metronidazole

Answer 4

T. vaginalis
G. lamblia
various different anaerobic bacteria

Question 5

describe the spectrum of metronidazole

Answer 5

anaerobes

• T. vaginalis
• G. lamblia
• E. histolytica
• Helicobacter spp.
• Campylobacter spp.
• Clostridium spp.

Question 6

adverse effects metronidazole

Answer 6

• metallic taste
• dry mouth
• nausea
• headache
• disulfiram-like effect

Question 7

describe the disulfiram-like effect that can occur as a result of metronidazole

Answer 7

induces vomiting if patient consumes alcohol