T3-Metronidazole & Vancomycin Flashcards
What is the MOA of Metronidazole?
Starts out harmless, but once it is absorbed by an ANAEROBIC bacteria or protozoa, it gets converted into something that is toxic to the bacteria’s DNA
Is Metronidazole toxic or harmless to other microbes that aren’t anaerobic or a protozoa?
Harmless
Metronidazole is similar to _____ in that it is harmless in the body until it is absorbed by the bacteria.
Nitrofurantoin (UTI drug)
What is the MOA of Vancomycin?
Inhibits cell wall synthesis and promotes bacterial cell lysis and death
Vancomycin is similar to _____ by acting on the bacterial cell wall causing it to break down, swell and burst.
Beta lactams
Even though Vancomycin and Beta Lactams have similar MOA, there is one key thing that makes them different. Explain.
Vancomycin does not interact with PBPs like beta lactams. Instead vancomycin disrupts the cell wall by binding to molecules that serve as precursors for cell wall biosynthesis (the building blocks)
What are the two meds that treat C. Diff?
MetronidaZOLE and Vancomycin
What are the indications of Metronidazole?
Abdominal bacteria (anaerobes)
Parasites (protozoa)
C.diff
H. pylori
One of the indications of Metronidazole is for abdominal bacteria (anaerobes). Where can you find anaerobes? What does this mean?
Most frequently in the gut; use it for infections that are BELOW the diaphragm–so if someone is going to have abdominal surgery, we will use the drug prophylactically
What all is needed to defeat the H.Pylori GI ulcer?
Metronidazole
Tetracycliine
Bismuth subsalicylate (pepto bismol)
Proton pump inhibitor or H2 blocker
^ALL IS NEEDED TO DEFEAT THE H.PYLORI!!!
What are the adverse effects of Metronidazole?
N/D
Metallic taste
Peripheral neuropathy
Disulfiram reaction?
Metronidazole treats C. diff. Metronidazole also has an adverse effect of N/D. Will we see the adverse effect of N/D with C. diff patients taking Metronidazole?
No, since it kills the C. diff
Metronidazole also has a metallic taste to it. What other class has that adverse effect?
Macrolides–clarithromycin
Metronidazole has peripheral neuropathy as an adverse effect. Is this common or rare? Is this serious?
RARE- yes, if someone reports numbness or tingling we need to take that seriously!!!
What does old evidence say about Metronidazole and alcohol?
The use of alcohol with this drug may cause a disurlfiram reaction (heart attack in pill form) –even just a little alcohol can make you SICK AS A DOG. Even alcohol from vanilla flavoring or mouth wash!
What does the new evidence say about Metronidazole and alcohol?
New evidence states that there is no reaction with alcohol and metronidazole
What are some other names we can think of when talking about Vancomycin?
Mississippi mud can cause redneck syndrome
Does vancomycin bind with penicillin-binding proteins that mess up the cross links in the bacterial cell wall, making it weak?
NO-Vancomycin doesn’t bind to the PBP protein and it doesn’t have that beta-lactam ring!
Vancomycin DOES bind with and deactivate precursors (the building materials) for the wall!!!!
What are the adverse effects of Vancomycin?
Nephrotoxicity
Ototoxicity
Thrombophlebitis
Red man syndrome
Is Vancomycin tough on the kidneys?
Yes-it can cause nephrotoxicity
How is vancomycin tough on the kidneys?
It is dose dependent-if the dose is appropriate, we don’t worry. If the dose is too hight, we worry
So Vancomycin is tough on the kidneys, and that is because it is very much dose-dependent. So we just need to dose it correctly. Why is this difficult to do?
Everyone processes the drug a little differently
Since Vancomycin is tough on the kidneys because it is dose-dependent and we need to dose it correctly, even though thats hard to do since everyone processes the drug differently…what must we check to make sure everything is right?
Check the blood levels!
Since Vancomycin is tough on the kidneys because it is dose-dependent and we need to dose it correctly, even though thats hard to do since everyone processes the drug differently, and we need to check the blood levels to this…what specifically do we need to do to get the accurate level?
Check the vancomycin trough–this must be done within 30 minutes of the next dose
Patients taking vancomycin have to have the blood levels checked to check the vancomycin trough–but something else needs to be monitored. What is that and when would we know we need to lower the dose of vancomycin?
Check serum creatinine levels; if they increase by 50%, we need to lower the dose!
Ototoxicity is another adverse effect of Vancomycin. Is this common or rare, and when do we worry about this the most?
Rare- worry when patient is taking other ototoxic drugs
Vancomycin is tough on the ___. When you infuse it, it can hurt. It can irritate a person’s veins to the point that they develop _____ (another adverse effect of vancomycin). So if you can, you want to _______. Is this a common or rare problem?
Veins
Thrombophlebitis
Rotate IV sites
COMMON
Vancomycin also has an adverse effect of Red mans syndrome. How does it occur, what is it, and is it something we worry about?
Vancomycin can cause SOME people to release a bunch of histamine. It makes a persons skin turn RED, they might ITCH, they might get a little TACHYCARDIC, and they might become a little HYPOTENSIVE.
This is not anaphylactic shock–so no we don’t worry about it. All we need to do is SLOW DOWN THE NEXT INFUSION–we can pre-medicate with Benadryl for future doses
If someone is taking Vancomycin and they start to experience one of the adverse effects and begin to look red and their IV is infusing over 1 hour. What can we do for the next infusion?
SLOW IT DOWN. If we are infusing over 1 hour, next time infuse it over 2. Also next time pre-medicate with Benadryl
If someone is taking Vancomycin and has had red mans syndrome, why do we pre-medicate with Benadryl?
Because benadryl works by blocking the effects of Histamine
Is Vancomycin polar or lipid soluble?
POLAR-IT IS NOT LIPID SOLUBLE
If we give Vancomycin PO, will it absorb?
NO, it will stay in the GI tract
So when would we give Vancomycin PO if it only will stay in the GI tract that way (since it is not lipid soluble)?
To treat C. diff!
When we are giving a patient IV Vancomycin, we need to be worrying about their _____. If they don’t have good ___ output that is a problem. What do we check with Vancomycin? And when is that usually done?
Kidneys; urine
Trough levels–we often check the trough BEFORE THE FORTH DOSE
If patients have had an allergic reaction to penicillin, can we give them vancomycin?
Yes
