Micro - Antimicrobials (Antifungals & Parasite Treatment) Flashcards
Pg. 189-191 in First Aid 2014 Sections include: -Antifungal therapy -Amphotericin B -Nystatin -Azoles -Flucytosine -Echinocandins -Terbinafine -Griseofulvin -Antiprotozoan therapy -Chloroquine -Antihelminthic therapy (49 cards)
Which antifungal drug inhibits lanosterol synthesis?
Terbinafine
Which type of antifungal drug inhibits ergosterol synthesis? Give 6 examples of this type of drug.
Azoles; (1) Fluconazole (2) Ketoconazole (3) Clotrimazole (4) Miconazole (5) Itraconazole (6) Voriconazole
Which type of antifungal drug inhibits cell wall synthesis? Give 3 examples of this type of drug.
Echinocandins; (1) Caspofungin (2) Micafungin (3) Anidulafungin
Which type of antifungal drug forms membrane pores? Give 2 examples of this type of drug.
Polyenes; (1) Amphotericin B (2) Nystatin
Which antifungal drug inhibits nucleic acid synthesis?
5-Flucytosine
Draw a visual depicting the methods of antifungal therapy, which include: (1) Lanosterol synthesis (2) Ergosterol synthesis (3) Cell wall synthesis (4) Forms membrane pores (5) Nucleic acid synthesis. Match of these methods to their specific drugs.
See p. 189 in First Aid 2014 for visual
What is the mechanism of Amphotericin B?
Binds ergosterol (unique to fungi); Forms membrane pores that allow leakage of electrolytes; Think: “ amphoTERicin “TEARs” holes in the fungal membrane by forming pores”
In general, what is the clinical use of Amphotericin B? What are specific examples of conditions in which Amphotericin B is used? Include details of use, where applicable/necessary.
Serious, systemic mycoses. Crypotococcus (amphotericin B with/without flucytosine for cryptococcal meningitis), Blastomyces, Coccidioides, Histoplasma, Candida, Mucor. Intrathecally for fungal meningitis.
What is used in supplement to Amphotericin B, and why?
Supplement K+ and Mg2+ because of altered renal tubule permeability
What are 6 toxicities associated with Amphotericin B?
(1) Fever/chills (“shake and bake”) (2) Hypotension (3) Nephrotoxicity (4) Arrhythmias (5) Anemia (6) IV phlebitis (“AMPHOTERRIble”).
What can decrease the nephrotoxicity associated with Amphotericin B?
Hydration lowers nephrotoxicity.
What kind of preparation of Amphotericin B lowers its toxicity?
Liposomal amphotericin B lowers toxicity.
With which other antifungal does Nystatin share its mechanism? What is that mechanism?
Same as amphotericin B; Binds ergosterol (unique to fungi) & Forms membrane pores that allow leakage of electrolytes;
What is the form of nystatin, and why?
Topical form because too toxic for systemic use.
What are 2 clinical uses of nystatin?
“Swish and swallow” for oral candidiasis (thrus); Topical for diaper rash or vaginal candiasis
What are 6 examples of Azoles?
(1) Fluconazole (2) Ketoconazole (3) Clotrimazole (4) Miconazole (5) Itraconazole (6) Voriconazole
What is the mechanism of Azoles?
Inhibit fungal steroid (ergosterol) synthesis, by inhibiting the cytochrome P-450 enzyme that converts lanosterol to ergosterol
In general, what is the clinical use of Azoles?
Local and less serious systemic mycoses
What are 2 clinical uses of Fluconazole?
Fluconazole for chronic suppression of cryptococcal meningitis in AIDS patients and candidal infection of all types
What are 3 clinical uses of Itraconazole?
Itraconazole for Blastomyces, Coccidioides, Histoplasma
What is the clinical use of Clotrimazole? Which other Azole shares this clinical use?
Clotrimazole and Miconazole for topical fungal infections
What are 2 toxicities associated with Azoles?
(1) Testosterone synthesis inhibition (gynecomastia, esp. with ketoconazole) (2) Liver dysfunction (inhibits cytochrome P-450)
Which Azole is most associated with testosterone synthesis inhibition? Which condition does this cause?
Testosterone synthesis inhibition (gynecomastia, esp. with ketoconazole)
What is the mechanism of Flucytosine?
Inhibits DNA and RNA biosynthesis by conversion of 5-fluorouracil by cytosine deaminase
