DNA synthesis inhibitors: Metronidazole

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Introduction0:00–0:26

DNA synthesis inhibitors are a group of antibiotics that target the synthesis of DNA in bacteria and other organisms. MetroNIDAZOLE, a five nitroimidazole prevents the synthesis of nucleic acids which are the building blocks of DNA and is effective against many bacteria and protozoans.
MetroNIDAZOLE and related five nitroimidazoles are relatively nontoxic to humans. This is because in order to function, they need to be reduced by a protein called ferredoxin which contains sulfur and iron.

Mechanism of action0:26–1:10

This protein is commonly found in anaerobic bacteria and protozoans but is not as available in humans and aerobic bacteria.
Now, this protein can donate an electron to metroNIDAZOLE causing it to form free radicals which will damage the DNA, causing it to fragment without the DNA as a template.
The organism can't synthesize any more nucleic acids like DNA or M RN, which will lead to cell death. MetroNIDAZOLE can be taken orally, but it's also available in an IV form.
And as topical creams, it penetrates well into body tissues and fluids, including vaginal secretions, seminal fluid, saliva, breast milk and cerebrospinal fluid and crosses over the placenta.

Indications1:10–2:32

This medication can treat many anaerobic bacterial infections like clostridioides difficile which can cause pseudomembranous enterocolitis in people taking other antibiotics.
Another common organism treated by this medication is helicobacter pylori, a common bacteria that causes gastritis and peptic ulcers.
However, it should be used in combination with other antimicrobials and proton pump inhibitors as part of a triple therapy for the best outcome when treating this condition.
Next, Gardnerella, vaginalis and other anaerobes that can cause bacterial vaginosis are all treated by metroNIDAZOLE for protozoan infections.
Its the medication of choice for amoebiasis and infection of the gut caused by entamoeba histolytica. It's the medication of choice against trichomonas, vaginalis as well which causes vaginal trichomoniasis.
Finally, metroNIDAZOLE is highly effective against giardiasis or beaver fever, which is an infection of the gut caused by giardia lamblia.
MetroNIDAZOLE is metabolized in the liver and it's an inhibitor of cyp 450 enzymes. So it can slow down the metabolism of other medications like warfarin, which are also broken down by this enzyme.

Side effects2:32–3:19

Common side effects of metroNIDAZOLE include decreased appetite, nausea, a metallic taste in the mouth, headaches and stomach cramps in high doses or in chronic treatment, neurological effects such as seizures, confusion and peripheral neuropathy can be seen.
It is usually not recommended during the first trimester of pregnancy as a precaution. Finally, although it is not well understood why metroNIDAZOLE may cause a disulfiram like reaction in some people where if the person drinks alcohol while taking metroNIDAZOLE, they experience severe nausea, vomiting and headaches.

Memory palace3:19–4:30

Now, we want to make a simple and fun mnemonic that'll help you efficiently memorize and retain all these pharmacology facts.
So first let's put a giant metronome in a garden scene for metroNIDAZOLE. A chrome colored cell is crushed under the metronome to help you remember this drug inhibits cytochrome P 450.
Now, there's a giant fish bowl here to help you remember, metroNIDAZOLE is effective against anaerobic bacteria for the decorations in the fish bowl.
There's a closet for clostridioides, a little helicopter for Helicobacter and a plastic gardener for Gardnerella for the protozoans.
Lets use a giant gerbil to represent Giardia. He and his buddies, a giant amoeba representing entamoeba and a triceratops representing trichomonas are hanging out and eating all the flowers in the garden for the important side effects.
Lets put a couple of empty beer bottles by the gerbil to represent the disulfiram like reaction. His arms are covered in bandages to represent neurotoxicity like peripheral neuropathy.
All right. As a quick recap.

Review4:30–4:55

MetroNIDAZOLE is an antibiotic that targets anaerobes like clostridioides and protozoans like Giardia. This is because these organisms have a lot of the protein called ferredoxin that allows metroNIDAZOLE to generate free radicals.
These free radicals will damage the DNA. So additional nucleic acids cannot be synthesized.
But wait, there's more. Here's a mind map with all of the mnemonics from the video.

Mind map4:55–5:06

Go ahead and pause the video. So you can test yourself to see what you remember.
Stay tuned for the answers at the end.
DNA synthesis inhibitors: Metronidazole: Video | Osmosis