Antifungal Medications Flashcards
Amphotericin B: MOA
- Binds ergosterol
- Alters membrane permeability
Amphotericin B and CNS activity
Poor penetration
Main adverse reaction with Amphotericin B use (1)
Nephrotoxicity, caused by vasoconstriction of afferent renal arterioles
T/F Amphotericin B has an infusion related side effect
True, if given rapidly patients may report shaking, chills, fever
*Pre-medicate with NSAIDS, Aspirin
Amphotericin B: Spectrum of Activity
All fungal infections (except rare instances)
Amphotericin B Lipid Complex
New Amphotericin is given as a lipid complex, which some studies show DECREASED NEPHROTOXICITY
5-Fluocytosine: MOA
- Penetrates fungal cell wall
- Altered by cytosine deaminase
- Inhibits pyrimidine metabolism
5-Fluocytosine and CNS
Good CNS penetration
Main adverse reaction associated with 5-Fluocytosine (1)
Bone marrow hypoplasia
When should 5-Fluocytosine be used?
Serious infections:
- Candida
- Cryptococcus
T/F 5-Fluocytosine is often administered with Amphotericin B
True, resistance is problematic when used alone
2 broad categories of Azoles
- Imidazole
2. Triazole
1 drug in the Imidazole category
Ketoconazole
4 drugs in the Triazole category
Fluconazole
Itraconazole
Voriconazole
Posaconazole
Azole: MOA
- Interfere with fungal cytochrome P450 enzymes
- Conversion of Lanosterol to Ergosterol cannot occur
Which Azole broad category is used the most. Why?
Traizoles have increased affinity for fungal p450 enzymes
Ketoconazole causes decrease in what 2 serum levels
- Testosterone
- Adrenocorticotropic hormone
Drug interactions with Azole use (3)
- Antacids
- Cycolsporin (increased serum)
- Warfarin (increased anticoagulation)
Which Azole drug is not commonly used in the United states?
Ketoconazole
Which Azole is the primary treatment for CNS fungal infections
Fluconazole
T/F Fluconazole is altered by gastric pH/Food in stomach
False
What Azole drug is commonly used to treat systemic fungal infections
Itraconazole
Which Azole is used to treat invasive aspergillosis
Voriconazole
T/F Voriconazole serum levels are decreased in patients who have recently had a high fat meal
True
What are 2 adverse reactions with Voriconazole use
- p450 Interactions
2. Visual disturbances
What Azole is used in severely immunocompromised patients in treatment of Candida and Aspergillus infections?
Posaconazole
T/F Posaconazole inhibits CYP34A
True
Caspofungin acetate: MOA
Inhibition of gluten synthesis
Why is caspofungin generally used as a second line drug?
Phlebitis, elevated Serum creatinine
What is the indicated use of caspofungin acetate (2)
- Invasive aspergillosis
2. Candidiasis
Griseofulvin: MOA
Disrupts mitotic spindle structure
T/F Griseofulvin is a p450 suppressor
False. It is an inducer, meaning increased metabolism
Main use of griseofulvin
Dermatophytosis
Terbinafine: MOA
- Squalene epoxidase inhibitor
- Inhibits sterol synthesis
T/F Terbinafine interacts with p450
True
Main use of Terbinafine
Onychomycosis (fungus under nail) after topical therapy has failed
T/F Terbinafine is safe to give to pregnant patients
False
3 main drugs to treat oral candidiasis (thrush)
- Nystatin (rinse)
- Clotrimazole troches (tablet)
- Amphotericin B suspension (rinse)
