Antifungals

Question 1

True or False: Antifungals are a group of antibiotics

Answer 1

False: They are a group of antimicrobials

Question 2

What potent antifungal is used to treat deep mycoses, administered primarily IV, and not given PO because it is poorly absorbed from the GI tract?

Answer 2

Amphotericin B

Question 3

What is the mechanism of action for Amphotericin B

Answer 3

It binds to and damages ergosterol

Question 4

What is ergosterol?

Answer 4

A major component of the fungal membrane

Question 5

What does damaging ergosterol do?

Answer 5

It creates holes in the fungal cell membrane and allows for critical cellular components to leak from the fungal cell

Question 6

When critical cellular components leak from the fungal cell wall, what effect does this produce?

Answer 6

A fungicidal or fungistatic effect based on the concentration of the drug at the fungal infection site

Question 7

What is the most common and most significant side effect of Amphotericin B?

Answer 7

Nephrotoxicosis

Question 8

Due to its nephrotoxic side effects, what form was created to better deliver Amphotericin B to the fungal infection?

Answer 8

Liposomal form

Question 9

What is the Liposomal form of Amphotericin B?

Answer 9

Amphotericin B is encapsulated in a liquid capsule that reduces nephrotoxicity

Question 10

Azoles are otherwise know as what?

Answer 10

Imidazole derivatives

Question 11

What are the two groups of Azoles?

Answer 11

Imidazoles and Triazoles

Question 12

Imidazoles contain what?

Answer 12

Two nitrogen atoms

Question 13

Triazoles contain what?

Answer 13

Three nitrogen atoms

Question 14

What are commonly used Azoles?

Answer 14

Ketoconazole
Itraconazole
Fluconazole
Miconazole
Voriconazole
Clotrimazole

Question 15

What is the prototype imidazole?

Answer 15

Ketoconazole

Question 16

Which antifungal is the first drug of choice for long-term treatment?

Answer 16

Imidazoles

Question 17

What is the mechanism of action for azoles/imidazoles?

Answer 17

Interfere with the enzyme that synthesizes erogosterol molecule

Question 18

How many days of treatment does it take for imidazoles to become fungicidal?

Answer 18

5 to 10 days

Question 19

Do imidazoles cause nephrotoxicity?

Answer 19

No

Question 20

What are the most common side effects of imidazoles?

Answer 20

GI side effects

Vomiting at higher doses occurs more commonly in cats

Question 21

In what imidazole/azole has hepatotoxicity been reported?

Answer 21

Ketoconazole

Question 22

What is a more potent antifungal than ketoconazole, is more effective at treating Aspergillus than ketoconazole, causes fewer GI side effects?

Answer 22

Itraconazole

Question 23

What is one of the drugs of choice for treating guttural pouch mycosis in horses caused by Aspergillus?

Answer 23

Itraconazole

Question 24

What other antifungal is more potent than ketoconazole, is less effective at treating deep mycoses than itraconazole and does not require an acidic pH to be absorbed like the other antifungals?

Answer 24

Fluconazole

Question 25

Which antifungal is the drug of choice for treating mycotic meningitis?

Answer 25

Fluconazole

Question 26

Fluconazole is excreted mostly in the kidney, and thus achieves therapeutic concentrations in the urine making it the drug of choice to treat what?

Answer 26

Fungal cystitis

Question 27

Which antifungals are used to treat topical yeast infections and superficial dermatophytes?

Answer 27

Clotrimazole & Miconazole

Question 28

Which antifungal is used for intranasal infusions to treat nasal aspergillosis?

Answer 28

Clortimazole