Chapter 35 (micro 50): Anti-fungals

Question 1

What is the mechanism of action of polymers

Answer 1

Bind to ergosterol causing disruption of cell membrane

Question 2

What is the mechanism of action of allylamines

Answer 2

Block ergosterol synthesis in cell membrane

Question 3

What is the mechanism of action of azoles

Answer 3

Block ergosterol synthesis in cell membrane

Question 4

What is the mechanism of action of echinocnadins

Answer 4

Inhibit cell wall synthesis

Question 5

What is the mechanism of action of pyrimidine inhibitor

Answer 5

Inhibits DNA and protein synthesis

Question 6

What pathogens does flucytosine treat mostly

Answer 6

Cryptococcus, candida

Question 7

What pathogens does echinocgandins mostly treat

Answer 7

Candida, aspergillosis

Question 8

What pathogens does terbinafine usually treat

Answer 8

Dermatophytes

Question 9

What pathogens does fluconazole mostly treat

Answer 9

Candida, cryptococcus

Question 10

What inherent toxicities are associated with amphotericin B (micro)

Answer 10

Nephrotoxicity, anemia, infusion reactions

Question 11

What activity does terbinafine inhibit

Answer 11

Squareness epoxidase acitvity

Question 12

What is potassium iodide used against

Answer 12

Cutaneous sporotrichosis

Question 13

What are some side effects of potassium iodide

Answer 13

Metallic taste, thyroid dysfunction, rash, salivary swelling

Question 14

describe the mechanism of action of flucytosine

Answer 14

converted in several steps to 5-FdUMP, which inhibits thymidylate synthase and thereby interferes with DNA synthesis

Question 15

what are the clinical applications of flucytosine

Answer 15

candidiasis, cryptococcosis, chromomycosis

Question 16

what are some adverse effects with flucytosine

Answer 16

bone marrow suppression, cardiotoxicity, GI disturbance

Question 17

what is a contraindication to flucytosine

Answer 17

pregnancy

Question 18

what accounts for resistant to flucytosine

Answer 18

mutations in cytosine permeate or cytosine deaminase

Question 19

who should flucytosine be use with caution in

Answer 19

patients with renal impairment

Question 20

what is the mechanism of action of griseofulvin

Answer 20

binds to tubular and a microtubule-associated protein, thereby disrupting assembly of the mitotic spindle

Question 21

what is the clinical application of griseofulvin

Answer 21

fungal infection of skin, hair or nail to trichophyton, microsporum, or epidermophyton

Question 22

what levels can griseofulvin increase

Answer 22

protoporphyrin levels

Question 23

what are some adverse effects seen with griseofulvin

Answer 23

vertigo, blurred vision, hepatotoxicity, serum sickness

Question 24

what are some contraindication to griseofulvin use

Answer 24

pregnancy, porphyria and hepatic failure

Question 25

at what interval is griseofulvin taken

Answer 25

6 hour intervals

Question 26

what is the mechanism of action of terbinafine, naftifine, butenafine

Answer 26

inhibit conversion of squalene to lanosterol by inhibiting squalene epoxidase

Question 27

what is the main clinical application of terbinafine, naftifine, butenafine

Answer 27

tinea infections

Question 28

what drugs can alter plasma levels of terbinafine

Answer 28

cimetidine increases it and rifampin decreases it

Question 29

what is the mechanism of action of the imidazole antifungals

Answer 29

inhibiting 14-alpha-sterol demethylase which inhibits conversion of lanosterol to ergosterol

Question 30

what are some adverse effects seen with ketoconazole

Answer 30

GI disturbance, hepatic dysfunction, gynecomastia, decreased libido, menstrual irregularities

Question 31

what is the mechanism of action of amphotericin B

Answer 31

bind to ergosterol and form pores that alter fungal membrane permeability and stability

Question 32

what are some adverse effects seen with amphotericin B

Answer 32

renal toxicity, cytokine storm, anemia, weight loss, GI disturbance

Question 33

what is the clinical application of nystatin

Answer 33

mucocutaneous candidiasis

Question 34

what is the mechanism of action of echincandins

Answer 34

non competitively inhibit synthesis of beta-(1,3)-D-glucans, which leads to disruption of cell wall integrity

Question 35

what is the clinical application of anidulafungin

Answer 35

esophageal candidiasis, candidermia

Question 36

what organ systems is amphotericin primarily used for

Answer 36

severe systemic fungal infections

Question 37

what does amphotericin toxicity result form

Answer 37

non-selective binding to mammalian cholesterol membranes

Question 38

what type of amphotericin administration is needed for fungal CNS infections

Answer 38

intrathecal administration

Question 39

what is the biggest amphotericin toxicity

Answer 39

renal tubular acidosis type 1 (renal damage)

Question 40

what fungi does itraconazole treat

Answer 40

systemic infections with dimorphic fungi (histoplasmosis, blastomycosis, coccidioidomycosis, sporothrix)

Question 41

what does ketonazole inhibit

Answer 41

17,20-desmolase, the first step of steroid synthesis of cholesterol