Lecture 4: Anti-Fungal Agents Flashcards
____ is used to treat superficial infections
A. Ketoconazole
B. Miconazole
C. Fluconazole
D. Griseofulvin
D. Griseofulvin
Which four anti-fungal drugs are used to treat systemic, subcutaneous fungal infections?
Keto/Mico/Fulco/Itra-conazole
What type of therapy is indicated for patients who are febrile, neutropenic and do NOT responds to broad spectrum antibacterial treatment? Which broad-spectrum anti-fungal drugs should be used?
Empiric Anti-Fungal Therapy
1. Miconazole
2. Amphotericin B
Prophylactic Antifungal therapy is commonly used in which patient populations?
A. Immunocompromised
B. Immunocompetent
A. Immunocompromised
What are the two major groups of -azoles?
Imidazole
Triazoles
Which three drugs can be used to treat mild to moderate Tinea infections?
Clotrimazole
Miconazole
Tolnaftate
Which five drugs are used to treat moderate-severe Tinea infections?
Ketoconazole
Miconazole
Fluconazole
Itraconazole
Terbinafine
Which two drugs can be used to treat severe Tinea infections?
Griseofulvin and Ketoconazole
True or False: Drugs that end in -azole can be used to treat Tinea Versicolor
True
The -azoles, Nystatin, Terbinafine and Amphotericin B are used to treat:
A. Candidiasis
B. Tinea Versicolor
C. Dermatitis
A. Candidiasis
Amphotericin B and Nystatin affects:
A. Ergosterol Synthesis
B. Cell wall Synthesis
C. Nuclear Division
D. Membrane Function
D. Membrane Function
Azoles affects:
A. Ergosterol Synthesis
B. Cell wall Synthesis
C. Nuclear Division
D. Membrane Function
A. Ergosterol Synthesis
Griseofulvin affects:
A. Ergosterol Synthesis
B. Cell wall Synthesis
C. Nuclear Division
D. Membrane Function
C. Nuclear Division
Echinocandins affect:
A. Ergosterol Synthesis
B. Cell wall Synthesis
C. Nuclear Division
D. Membrane Function
B. Cell wall Synthesis
Squalene, a precursor sterol, is converted to lanosterol via:
Squalene monooxygenase
Which two molecules inhibit Squalene Monooxygenase?
Terbinafine and Tolnaftate
- Accumulation of squalene
The -azoles inhibit this enzyme:
A. Squalene monooxygenase
B. 14-a demethylase (P450)
B. 14-a demethylase (P450)
- Accumulation of lanosterol
Which enzyme converts lanosterol to ergosterol?
A. Squalene monooxygenase
B. 14-a demethylase (P450)
B. 14-a demethylase (P450)
Amphotericin B binds to ____ in the fungal cell membrane
A. phospholipids
B. cholesterol
C. sterols (ergosterol)
D. mycolic acid
C. sterols (ergosterol)
As a result of Amphotericin B binding to sterols, ___ is formed in cell membrane, ____ increase and ___ are lose
pores/channels; permeability increases; K
Ergosterol can also bind to which mammalian cells?
Kidney cells
Erythrocytes
How must ergosterol be given?
A. Orally
B. Anally
C. Parenterally
D. IV
E. IM
C. Parenteral
What are the two AE associated with ergosterol?
Nephrotoxicity and reversible Anemia (hypochromic, normocytic)
True or False: ergosterol is used to treat localized infections
False - systemic
True or False: Systemic triazoles are more quickly metabolizes and have more of an effect on human sterol synthesis than imidazoles
False - systemic triazoles are more SLOWLY metabolized and have LESS of an effect on human sterol synthesis than imidazoles
All -azoles have a triazole nucleus. It contains two Nitrogens. If the third molecule is a carbon it is a ____ and if it is a N it is a _____
C = imidazole
N = triazole
Both imidazole and triazoles inhibit which enzyme?
sterol-14-a-demethylase (P450 enzyme)
- leads to demethylation of lanosterol
Clotrimazole, Miconazole, and Ketoconazole are ______
A. Triazoles
B. Imidazoles
B. Imidazoles
True or False: Itraconazole and Fluconazole are Triazoles
True
Why do endocrine abnormalities can result from Ketoconazole use? Examples?
Ketoconazole inhibits steroid biosynthesis
Females: menstrual abnormalities
Males: gyecomastia
Why can Ketoconazole result in DDI?
Inhibits P450
True or False: Miconazole has low toxicity and is used for systemic fungal infections
True
True or False: Fluconazole is used for systemic infections and has low toxicity
True
Which drug disrupts cell’s mitotic spindle structure, therefore arresting metaphase of cell division, as well as is deposited in keratin precurosor cells (hair, skin nails)?
A. Griseofulvin
B. Ketoconazole
C. Fluconazole
A. Griseofulvin
- Use is 2-4 wks to 6 mths
Which drug mainly treats skin infections (dermatophytoses)?
A. Griseofulvin
B. Ketoconazole
C. Fluconazole
A. Griseofulvin
Like Amphotericin B, Nystatin binds to sterols in the fungal ___ ____
A. Cell Membrane
B. Cell Wall
C. Cytoplasm
A. Cell Membrane
True or False: Nystatin is absorbed via: skin, mucous membranes, and GI tract
False - it is NOT
True or False:
Nystatin can be used via parentral use but Amphotericin B cannot
False - Nystatin CANNOT (too toxic) be used parentrally but Amphotericin B CAN!
Which of the following conditions does Nystatin typically treat?
A. Dermititis infections
B. Candidal infections
C. Chicken Pox
B. Candidal infections
___ interferes with sterol biosynthesis by inhibiting squalene monooxygenase, which result in decreased ergosterol and accumulation of squalene
A. Amphotericin B
B. Nystatin
C. Tolnaftate
C. Tolnaftate
True or False: Nystatin and Tolnaftate have low toxicity
True
Terbinafine hydrochloride has the same mechanism as Tolnaftate, meaning it inhibits _____ enzyme, which results in decreased ergosterols and accumulation of squalene
squalene monooxygenase
_____ is the first antifungal to belong to the echinocandins class of antifungal agents
Caspofungin
_____ inhibit synthesis of B1,3-D-glucan, an essential polysaccharide component of the CELL WALL of filamentous fungi
Echinocandins
What are the main uses of Echinocandins?
Esophageal candidiasis and invasive aspergillosis (for patients who are REFRACTORY or INTOLERANT to other antifungals!!)
