Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
What are the most widely prescribed nucleic acid inhibiting antibacterial drugs?
|
The Quinolones
|
|
|
What are three other less commonly prescribed nucleic acid inhibitors?
|
-Nitrofurantoin
-Rifampin -Metronidazole |
|
|
What is the mechanism of action of Nitrofurantoin?
|
Nitroreductase enzyme in the bacteria convert Nitrofurantoin into reactive compounds that behave like free radicals and damage DNA.
|
|
|
What is the primary indication for Nitrofurantoin? Why?
|
UTI's - because this is the only place where effective drug concentrations are achieved.
|
|
|
What type of UTI's can Nitrofurantoin treat? Organisms?
|
Bladder infections due to E. coli, Enterococcus, and Staphs - not pyelonephritis.
|
|
|
What nonalarming side effects can be seen with Nitrofurantoin?
|
N/V
Fever/chills/hypersensitivity |
|
|
What are 5 more alarming side effects that Nitrofurantoin can cause?
|
-Pulmonary reactions - both acute and chronic fibrosis
-Acute/chronic Liver damage -Leukopenias of all white cells -Acute Hemolytic anemia |
|
|
In what patients can Nitrofurantoin cause acute hemolytic anemia?
|
Those with G6PD deficiency
|
|
|
Despite the adverse side effects that Nitrofurantoin can cause, how often is it used?
|
Pretty often
|
|
|
What is Rifampin's mechanism of action?
|
It binds the Beta subunit of RNA polymerase and inhibits mRNA synthesis
|
|
|
Are Rifampin and Nitrofurantoin bacterostatic or bactericidal?
|
Both are Bactericidal
|
|
|
What is the major use of Rifampin?
|
Tuberculosis
|
|
|
What is another use of Rifampin in addition to treating Tuberculosis?
|
-Meningitis prophylaxis for both -Neisseria and Haemophilus flu B
|
|
|
Who would you want to put on Rifampin for meningitis prophylaxis?
|
Family members of patients that come down with it, or HC workers that come in close contact with patients w/ meningitis.
|
|
|
Why is Rifampin used for preventing meningitis with Neisseria and Hib?
|
Because it is very lipophilic and gets into the thick mucus in nasopharyngeal areas which is where the bugs live before going systemic.
|
|
|
What are the 2 main side effects that Rifampin can cause?
|
-Serious hepatotoxicity (rare)
-Induction of liver P450s which causes severe interaction with many other drugs |
|
|
What is an ironic drug interaction caused by Rifampin's upregulation of p450's?
|
It upregulates its OWN p450 so induces its own metabolism
|
|
|
When does the self-induced increased metabolism of Rifampin become important?
|
In longterm treatment when repeated doses of the drug are given which shortens the half life of Rifampin
|
|
|
When does the half life of Rifampin stabilize during longterm therapy with it?
|
When the liver P450s are maximally induced.
|
|
|
What other funny thing does Rifampin do?
|
Turns your skin, tears, saliva, and pee ORANGE!! (how ironic I just RAN and then ate an ORANGE)
|
|
|
What other nucleic acid inhibiting drug is similar to Nitrofurantoin?
|
Metronidazole
|
|
|
How is Metronidazole similar to Nitrofurantoin?
|
Both are activated by an enzyme in the bacteria itself.
|
|
|
What is the mechanism of action of Metronidazole?
|
Anaerobes reduce its nitro group, which results in a reactive product that disrupts DNA.
|
|
|
So what do all of the nucleic acid inhibiting antibacterials have in common?
|
They all are bactericidal
|
|
|
So what bacteria is Metronidazole specific for? Why?
|
ANAEROBES - only they have the nitro-reducing enzyme that activates Metronidazole.
|
|
|
What TYPES of anaerobes does Metronidazole cover?
|
Both gram positive and gram negatives.
|
|
|
What other organisms can be treated with Metronidazole?
|
Parasites
|
|
|
In addition to treating anaerobes, what are 3 other indications for Metronidazole?
|
-1st Choice for C. difficile
-Combination tx of H. pylori -Gardnerella vaginalis (bacterial vaginosis) |
|
|
What is the 2nd choice drug for treating C. difficile?
|
Vancomycin
|
|
|
What can actually happen if you try to treat a strain of C. difficule causing enterocolitis that is resistant to Metronidazole?
|
You can cause more enterocolitis
|
|
|
What are 3 toxic side effects of metronidazole?
|
-BM suppression
-Thrombophlebitis after IV infusion -Knocks out GI flora allowing for other Bacterial and Fungal (candida) superinfections |
