Flashcards in PHARM A56c: Antifungal Therapy Deck (21):
What are the major 3 components of the fungal cell wall?
Mannoproteins, B-(1,3)- and B-(1,6)-glucans, and chitin
What is the main component of the fungal cell membrane?
What class of anti-fungal drugs are membrane-disrupting agents?
What is the mechanism of action of polyenes? What is the prototype of this class?
Binds sterols (preferentially ergosterol), forming a pore that disrupts osmotic integrity of cell membrane- FUNGICIDAL
True or False: Polyenes penetrate into CSF, vitreous humor, and amniotic fluid.
False: they do NOT penetrate
What is Amphotericin B used for?
Serious systemic infections and fungal meningitis
What are the major complications of polyene/ amphotericin B?
What classes of antifungal drugs inhibit the synthesis of ergosterol?
Azoles and allylamines
What enzymatic step is inhibited by Allylamines (terbinafine)?
The conversion of squalene to squalene epoxide by qualene epoxidase
What enzymatic step is inhibited by azoles?
The conversion of lanosterol to ergosterol by 14-alpha-sterol demethylase
What are the two major classes of azoles and what is the prototype of each?
Imidazoles (ketoconazole) and triazoles (fluconazole)
What enzymes are especially important in drug-drug interactions with azoles?
What are the adverse effects associated with azoles?
Hepatotoxicity, hypertension, visual impairment, and inhibition of testosterone synthesis
Which antifungal is contraindicated for cardiac patients?
What adverse effects are associated with terbinafine?
Taste disturbances; hepatotoxicity
What class of antifungals are glucan synthesis inhibitors? What is the prototype?
What is the mechanism of action of micafungin?
Inhibit beta-1,3 glucan synthesis- Fungicidal
What is the mechanism of action of flucytosine?
Block fungal, DNA, RNA, and Protein synthesis--- fungistatic
What is the mechanism of griseofulvin?
Fungal spindle disrupter (mitosis inhibitor)-- Fungistatic
Where does griseofulvin accumulate in the body?
Keratin precursor cells