antifungals Flashcards

1
Q

action of antifungals?

A

treat and prevent fungal disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what do superficial mycoses affect?

A

scalp, nails, skin, mucous membranes (oral cavity, vagina)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do systemic mycoses affect?

A

internal organs; kidneys, lung, brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

examples of fungal pathogens?

A

eukaryotes; candida albicans, aspergiullus fumigatus, Cryptococcus neoformans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

main targets for antifungal drugs?

A

fungal cell wall, plasma membrane, nucleus (RNA and DNA synthesis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

an antifungal that targets the cell wall?

A

echinocandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the key component within the fungal cell wall?

A

B1,3 glucan - a skeletal component

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

mechanism of action of: echinocandins

A

(caspofungin, micafungin) - they inhibit B1,3 glucan synthesize, to block the synthesis of glucan (a component within the cell wall, essential for the fungal cell’s survival)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

examples of ‘fungicidal’ antifungals?

A

echinocandins, polyene antifungals - they kill fungal pathogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

examples of ‘fungastatic’ antifungals?

A

Azoles and Allylamines - drugs that inhibit growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

antifungals that target the plasma membrane?

A

polyene antifungals, azoles, allylamines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

mechanism of action of: polyene antifungals

A

bind to resident ergosterol, to form pores in the PM and disrupt plasma membrane integrity, causing a leakage of cell constituents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

examples of polyene antifungals?

A

amphotericin B, nystatin (used for oral and GI infections)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

side effects of polyene antifungals?

A

kidney failure with prolonged application

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Mechanism of action of: azoles (ergosterol biosynthesis inhibitors)

A

inhibit the enzyme; lanosterol C-14 demethylase, which then blocks ergosterol biosynthesis. this leads to an accumulation of toxic intermediates and causes growth arrest.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

two types of azole?

A

imidazole, triazole

17
Q

mechanism of action of: allylamines

A

inhibit an earlier step of ergosterol biosynthesis than azoles

18
Q

antifungals that target the nucleus?

A

flucytosine

19
Q

mechanism of action of: flucytosine

A

it is taken up by fungal cells and metabolised to form 5-flourouracil (5-FU); a toxic antimetabolite that inhibits fungal DNA and RNA synthesis.

20
Q

what causes resistance to antifungals?

A

decreased accumulation of the drug, inactivation of the drug, mutations in drug-target encoding genes

21
Q

examples of allylamines

A

terbinafine, amorolfine - target plasma membrane

22
Q

examples of echinocandins

A

micafungin, caspofungin