Antifungals

Question 1

Which antifungals target ergosterol?

Answer 1

Polyenes, triazoles and imidazoles.

Question 2

Which antifungals inhibit ergosterol synthesis?

Answer 2

Allymines.

Question 3

Which antifungals block the production of the beta-(1,3)-glucan protein damaging the cell wall?

Answer 3

B-3-glucan synthase inhibitors.

Question 4

Which antifungals target chitin synthase?

Answer 4

Nikkomycin and polyoxin.

Question 5

Which antifungals inhibit DNA/RNA synthesis?

Answer 5

Flucytosine.

Question 6

Which antifungals inhibit fungal cell mitosis?

Answer 6

Griseofulvin.

Question 7

List polyenes?

Answer 7

Nystatin.
Amphotericin B.

Question 8

How is nystatin used?

Answer 8

Mostly topical and local treatment (oral thrush).

Question 9

What is the effectiveness of absorption of nystatin?

Answer 9

Poor systemic absorption.
Poor oral bioavailability.
No drug interaction.

Question 10

List MOA of amphotericin B?

Answer 10

binds to ergosterols to form pores, leading to leakage of molecules causing oxidative damage.

Question 11

List the spectrum of activity of amphotericin B?

Answer 11

Candida, Aspergillus, Histoplasma, cryptococcus, and blastomyces.

Question 12

What is the excretion method of polyenes?

Answer 12

Excreted by kidney slowly through months.

Question 13

List the side effects of amphotecirin B?

Answer 13

Fever, chills, electrolyte abnormalities (hypokalemia), renal dysfunction, hematologic toxicity.

Question 14

Give an example of fluorocytosine?

Answer 14

5-fluorocytosine.

Question 15

List MOA of 5-fluorocytosine?

Answer 15

Inhibits thymidylate synthase and DNA synthase.

Question 16

List spectrum of activity of 5-fluorocytosine?

Answer 16

Candida and crptococcus.

Question 17

Resistance is common for which antifungal and how to fix it?

Answer 17

5-fluorocytosine.

Question 18

List the adverse effects of 5-fluorocytosine?

Answer 18

Bone marrow toxicity - pancytopenia - reversible.

Question 19

What is the mechanism of azoles?

Answer 19

Binds to ergosterol to form pores.

Question 20

List the spectrum of activity of azoles?

Answer 20

Candida, aspergillus, histoplasma, cyptococcus, blastomyces, coccidiode, dermatophytes.

Question 21

________ newer azoles with fewer side effects?

Answer 21

Triazoles.

Question 22

Which antifungals work by inhibiting sterol 14 alpha- demethylase?

Answer 22

The azoles.

Question 23

Adverse effects of the azoles are due to what?

Answer 23

Inhibition of mammalian steroid synthesis.

Question 24

Drug interactions with azoles are due to what?

Answer 24

Inhibition of cyt.P450 enzymes.

Question 25

Triazoles cause what?

Answer 25

Decrease potassium.

Question 26

What is the MOA of echinocandins?

Answer 26

Inhibits 1,3-B-D-glucan synthase.

Question 27

Echinocandins are used for what?

Answer 27

Aspergillosis and candidiasis.

Question 28

What are echinocandins used for?

Answer 28

Empiric antifungal therapy.

Question 29

What are the adverse effects of echinocandins?

Answer 29

Fever, histamine release, hypokalemia.

Question 30

Give an example of echinocandins?

Answer 30

Capsofungin.

Question 31

Echinocandins are metabolized by what?

Answer 31

Hydrolysis and N-acetylation.

Question 32

Which antifungal is not an inhibitor/inducer/substrate of CYP?

Answer 32

Echinocandins.

Question 33

List allylamines?

Answer 33

1- naftifine. 2- terbinafine. 3- butenafine.

Question 34

List properties of naftifine?

Answer 34

- only available as gel or cream. (Poor systemic absorption 4-6%). - no interactions found.

Question 35

What are the substrates for terbinafine?

Answer 35

1A2, 2C9/19, 3A4.

Question 36

_______ decreases terbinafine clearance by 33%

Answer 36

Cimetidine.

Question 37

________ increases terbinfine clearance by 100%?

Answer 37

Rifampin.

Question 38

What is the inhibitor of terbinafine?

Answer 38

2D6 strong.

Question 39

Terbinafine Increases ________ leavels, ________ (Cmax up 1.9 folds), ________ (t1/2 up to 400 hours), __________ (Cmax up 2 folds)

Answer 39

Nortriptyline, paroxetine, amitriptyline, desipramine.

Question 40

What is the inducer of terbinafine?

Answer 40

3A4 weak.

Question 41

terbinafine increases metabolism of ________ by 15%?

Answer 41

Cyclosporine.

Question 42

Which antifungal binds to microtubules/ disrupts mitosis?

Answer 42

Griseofulvin.

Question 43

Griseofulvin deposits where?

Answer 43

In keratin layers.

Question 44

__________ actively concentrate griseofulvin

Answer 44

Dermatophytes.

Question 45

Griseofulvin is used for what?

Answer 45

Infections of the skin, hair, nails; prolonged therapy.

Question 46

List toxicity of griseofulvin?

Answer 46

Headache, neuro and hepatotoxicity, photosensitivity, carcinogenic.

Question 47

List topical antifungals?

Answer 47

1- tolnaftate. 2- nystatin. 3- naftifine. 4- terbinafine.

Question 48

Topical antifungals are used for what?

Answer 48

Stratum corneum mucosa, cornea by dermatophytes and candida.

Question 49

Topical antifungals are not used for what?

Answer 49

Subcutaneous, nail or hair infections.

Question 50

Whitfields ointment contains what?

Answer 50

Benzoic + salicylic acid.