Antifungals and TB Flashcards
Steroid found in the cell membrane of fungi.
Ergosterol
Binds to ergosterol in the fungal cell membrane, creating pores to increase cell permeability and thus cause death.
Amphotericin MOA
Amphotericin mechanism of resistance.
The sterols (ergosterol) are altered in the membrane, so amphotericin cannot bind.
OR
There’s a decreased amount of sterols in the cell membrane.
Adverse reaction of Amphotericin
1) Kidney toxicity, causing the patient to waste K and Mg.
2) Idiosyncratic hypotension and arrhythmias.
3) Fever, chills, and rigors.
These antifungals bind to cyt P450 enzymes to inhibit 1,4-alpha demethylation of Lanosterol (fungal steroid found in cell membranes).
Azole antifungals
Adequate hydration may decrease the toxicity caused by this drug.
Amphotericin
Azole used for candida albicans.
Fluconazole
This antifungal has the least drug-drug interactions of all the azoles.
Fluconazole
Antifungal against Aspergillus (a fungus).
Voriconazole
Another azole antifungal.
Posaconazole
Need to be aware of this with all azole antifungals.
Drug-drug interactions!
Antifungal that’s part of the Echinocandin family.
Caspofungin
This antifungal inhibits beta 1,3-glucan.
Caspofungin
This antifungal works at a different site of action from the azoles and amphotericin.
Caspofungin
Also members of the Echinocandin family.
Micafungin
Anidulofungin
These bacteria have chains of mycolic acid (types of fatty acids).
Mycobacteria
Where does TB infection begin in the lungs?
Alveoli
Large or small TB droplets lodge in the alveoli?
Small
Why are the majority of TB bacilli destroyed or inhibited once inhaled?
Alveolar macrophages ingest them.
T/F: A small number of TB molecules multiply in the alveolar macrophages (intracellularly), and are released when the macrophages die.
TRUE
Immune responses soon develop to kill the bacilli.
Within how many weeks after infection does the immune system halt the multiplication of the tubercle bacilli, preventing further spread?
2-10 weeks
When is a person INFECTED with TB?
When their immune system tries to halt the multiplication of the tubercle bacilli.
What percent of people infected with TB will develop the disease?
10%
The TB infection is controlled by the immune system in what percent of people? They will not develop CLINICAL TB.
90%
What percent of the 10% infected that get the disease will develop it in the first two years?
5%