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Flashcards in Antifungals Deck (28):
1

Amphotercin B mech

Binds ergosterol (unique to fungi); forms membrane pores that allow leakage of electrolytes. "amphoTERicin 'tears' holes in the fungal membrane by forming pores

2

Amphotercin B Clinical Use

Serious, systemic mycoses. Cryptococcus (amphotercin B with/without flucytosine for cryptococcal meningitis), Blastomyces, Coccidioides, Histoplasma, Candida, Mucor. Intrathecally for fungal meningitis. Supplement K+ and Mg+2 because of altered renal tubule permeability.

3

Amphotercin B Toxicity

Fever/chills ('shake and bake'), hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis ('amphoterrible').

4

What can decrease the nephrotoxicity of Amphotercin?

Hydration

5

Liposomal amphotercin

decreases toxicity

6

Nystatin Mech

Same as amphotercin B.

7

Is Nystatin Oral, IV, IM Topical, Inhaled?

Topical! too toxic for systemic use

8

Nystatin clinical use

'Swish and Swallow' for oral candidiasis (thrush); topical for diaper rash or vaginal candidiasis

9

What are the Azoles?

Fluconazole, ketoconazole, clotrimazole, miconazole, itraconazole, voriconazole

10

Mech of Azoles

Inhibit fungal sterol (ergosterol) synthesis, by inhibiting the CYP-450 enzyme that converts lanosterol to ergosterol

11

Clinical use of Azoles

Local and less serious systemic mycoses

12

Which Azole is used for chronic suppression of cryptococcal meningits in AIDS patients and candidal infections of all types?

Fluconazole

13

Which Azole do you treat Blastomyces, Coccidioides, Histoplasma with?

Itraconazole

14

Which Azole do you use to treat topical fungal infections?

Clotrimazole and miconazole

15

Where are the toxicities/SE of the Azoles?

Testosterone synthesis inhibition (gynecomastia, esp with ketoconazole), liver dysfunction (inhibits CYP 450)

16

Flucytosine Mech

Inhibits DNA and RNA biosynthesis by conversion to 5-FU by cytosine deaminase

17

Clinical use of Flucytosine

Systemic fungal infection (esp. meningitis caused by Cryptococcus) in combination with Amphotercin B

18

Toxicity of Flucytosine

Bone Marrow Suppression

19

What are the Echinocandins?

Caspofungin, micafungin, anidulafungin

20

What is the mechanism of the Echinocandins?

Inhibits cell wall synthesis by inhibiting synthesis of beta glucan

21

What is the clinical use of Echinocandins?

Invasive Aspergillosis, Candida

22

What is the toxicity of Echinocandins?

GI upset, flushing (by histamine release)

23

Terbinafine mech

Inhibits the fungal enzyme squalene epoxidase

24

Clinical use of Terbinafine

Dermatophytoses (especially onychomycosis - fungal infection of finger or toe nails). Tinea fungi

25

Terbinafine Toxicity

GI upset, headaches, hepatotoxicty, taste disturbance

26

Griseofulvin Mech

Interferes with microtubule function; disrupts mitosis. Deposits in keratin containing tissues (i.e nails)

27

Clinical use of Griseofulvin

Oral treatment of superficial infection; inhibits growth of dermatophytes (tinea, ringworm)

28

Toxicity of Griseofulvin

Teratogenic, carcinogenic, confusion, headaches, increased P-450 and warfarin metabolism.