Exam 5 - Antifungals Stahelin Flashcards

(78 cards)

1
Q

what does amphoteric mean?

A

has both acidic and basic groups (can act as an acid or a base)

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

mycosamine on amphotericin B is important for

a. pore formation
b. binding to ergosterol
c. binding to cholesterol

A

b. binding to ergosterol

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

the OH at C35 of amphotericin B is important for

a. pore formation
b. binding to ergosterol
c. binding to cholesterol

A

a. pore formation

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

the hydroxyl on mycosamine is important for

a. pore formation
b. binding to ergosterol
c. binding to cholesterol

A

c. binding to cholesterol (not ergosterol)

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

amphotericin B drug class

A

polyenes

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

amphotericin B binds to _______, the predominant sterol in fungal cell membranes

A

ergosterol

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

which of the following is FALSE about amphotericin B pharmacokinetics?

a. poorly absorbed from GI tract
b. oral amphotericin B is only effective for GI infections
c. IV injection required for systemic infection
d. fungal meningitis has no treatment

A

d. fungal meningitis has no treatment

(intrathecal therapy)

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

amphotericin B adverse effects (3 of them; broad)

A

-infusion related
-renal damage
-liver abnormalities occasionally

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

how can we alleviate the infusion-related AE of amphotericin B? (2 ways)

A

-reduce rate of infusion
-premedicate with diphenhydramine and/or acetaminophen

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

what is the reversible and irreversible component of renal damage due to amphotericin B?

A

reversible: reduced renal perfusion
irreversible: renal tubular injury

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

renal tubular injury due to amphotericin B usually occurs after using how many grams?

A

> 4 g

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

DOC for life-threatening fungal infections

A

amphotericin B

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

which polyene drug, similar to amphotericin B, is used for superficial fungal infections?

A

nystatin

(too toxic for systemic administration)

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

which of the following is NOT a lipid formulation of amphotericin B?

a. C-AMB (fungizone)
b. ABCD (amphotec)
c. L-AMB (ambisome)
d. ABLC (abelcet)

A

a. C-AMB (fungizone)

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

in conventional amphotericin B, what is used as the solubilizing agent?

a. glycerin
b. deoxycholate
c. cyclodextrins
d. sodium lauryl sulfate

A

b. deoxycholate

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

which of the following is FALSE about lipid formulations of amphotericin?

a. they reduce nephrotoxicity
b. act as reservoir of amphotericin
c. amphotec is the only one that uses true liposomes
d. each formulation uses different lipids

A

c. amphotec is the only one that uses true liposomes

(ambisome not amphotec)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

allylamine antifungal drugs (4; slide 16-19)

A

-terbinafine
-naftifine
-butenafine
-tolnaftate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

MOA of terbinafine and other allylamines

a. inhibits squalene epoxidase
b. inhibits 14a-demethylase
c. inhibit synthesis of B(1-3)glucan
d. inhibits thymidylate synthase and protein synthesis

A

a. inhibits squalene epoxidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

MOA of azoles

a. inhibits squalene epoxidase
b. inhibits 14a-demethylase
c. inhibit synthesis of B(1-3)glucan
d. inhibits thymidylate synthase and protein synthesis

A

b. inhibits 14a-demethylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

MOA of echinocandins

a. inhibits squalene epoxidase
b. inhibits 14a-demethylase
c. inhibit synthesis of B(1-3)glucan
d. inhibits thymidylate synthase and protein synthesis

A

c. inhibit synthesis of B(1-3)glucan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

MOA of flucytosine

a. inhibits squalene epoxidase
b. inhibits 14a-demethylase
c. inhibit synthesis of B(1-3)glucan
d. inhibits thymidylate synthase and protein synthesis

A

d. inhibits thymidylate synthase and protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

cell death due to terbinafine results from accumulation of _______, not loss of ergosterol

A

squalene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

which is structurally DIFFERENT than terbinafine, but still inhibits squalene epoxidase?

a. naftifine
b. butenafine
c. tolnaftate

A

c. tolnaftate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

which of the following is available oral and topical?

a. terbinafine
b. naftifine
c. butenafine
d. tolnaftate

A

a. terbinafine

(others are only topical)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
largest class of antimycotics (aka antifungals) a. allylamines b. azoles c. echinocandins d. polyenes
b. azoles (> 20 drugs)
26
are azoles fungicidal or fungistatic?
fungistatic
27
which antifungal drug class works by inhibiting the demethylation of lanosterol, inhibiting its conversion to ergosterol?
azoles
28
what is the importance of the nitrogen on the 5-membered aromatic ring of azoles?
essential for binding iron in P450 enzyme
29
ketoconazole IC50 for candida 14a-demethylase enzyme vs human enzyme (values)
candida: 10^-9 M human: 10^-6 M (more selective for fungal enzyme)
30
first orally active azole (slide 26) a. fluconazole b. itraconazole c. isavuconazole d. ketoconazole
d. ketoconazole
31
be able to look at structural features of azoles
okay
32
what does the added methyl group on voriconazole do?
improved binding to fungal 14a-demethylase and increase spectrum
33
what does the furan ring of posaconazole do?
alters and increases spectrum of activity
34
posaconazole is available as what two dosage forms?
-oral (as suspension) -IV
35
which of the following is TRUE about isavuconazole? a. lipid-soluble b. prodrug c. structurally similar to itraconazole d. short half life
b. prodrug (a. is water soluble; c. is voriconazole; d. is long)
36
which of the following is FALSE about isavuconazole? a. prodrug is isavuconazonium b. isavuconazonium is cleaved by plasma esterases c. release active drug and pro-drug cleavage product d. cleavage product has long half life
d. cleavage product has long half life (short)
37
T or F: oteseconazole is used for high risk of recurring fungal or yeast infections
T
38
newest azole drug to be approved a. fluconazole b. posaconazole c. oteseconazole d. itraconazole
c. oteseconazole (approved in 2022)
39
example of CYP inducer that can dec triazole levels (slide 35)
rifampin
40
which of the following is NOT a correct drug interaction with ketoconazole? a. inhibits metabolism of terfenadine and cisapride b. decrease AUC and half life of triazolam c. increases bioavailability of cyclosporin d. rifampin reduces ketoconazole levels
b. decrease AUC and half life of triazolam (increase)
41
80% of fluconazole is excreted by the ______ unchanged
kidney
42
ketoconazole is a potent inhibitor of a. CYP2C9 b. CYP2C19 c. CYP3A4 d. CYP3A8
c. CYP3A4
43
put these CYPs in order by which metabolizes voriconazole the most in the liver: CYP3A4, CYP2C9, CYP2C19
CYP2C19 > CYP3A4 > > CYP2C9
44
posaconazole is metabolized in liver by _________
glucoronidation
45
which echinocandin is a synthetically modified glarea lozoyensis? a. caspofungin b. micafungin c. anidulafungin
a. caspofungin
46
which echinocandin is synthetically modified coleophoma empetri a. caspofungin b. micafungin c. anidulafungin
b. micafungin
47
which echinocandin is synthetically modified aspergillus nidulans? a. caspofungin b. micafungin c. anidulafungin
c. anidulafungin
48
echinocandins route of admin
IV
49
target enzyme of echinocandins a. dihydrofolate reductase b. b(1-3)glucan synthase c. chitin synthase d. squalene monooxygenase
b. b(1-3)glucan synthase
50
3 structural components of yeast cell wall
chitin glucan mannoprotein
51
-Disseminated and mucocutaneous candida -Salvage therapy in patients with aspergillosis who fail to respond to amphotericin B a. caspofungin b. micafungin c. anidulafungin
a. caspofungin
52
-mucocutaneous candida -Candida prophylaxis in bone marrow transplant patients a. caspofungin b. micafungin c. anidulafungin
b. micafungin
53
-Esophogeal candidiasis -Invasive candidiasis a. caspofungin b. micafungin c. anidulafungin
c. anidulafungin
54
longest half life and no known drug interactions a. caspofungin b. micafungin c. anidulafungin
c. anidulafungin
55
T or F: echinocandins are metabolized by liver CYPs
F (degraded in blood and in tissues)
56
rezafungin drug class a. allylamine b. azole c. echinocandin d. polyene
c. echinocandin
57
Novel, once-weekly echinocandin antifungal for adults with limited or no alternative treatment options (candidiasis). a. rezafungin b. ibrexafungerp c. flucytosine d. griseofulvin
a. rezafungin
58
oral, small molecule inhibitor of glucan synthase enzyme in fungi; used for vulvovaginal candidiasis a. rezafungin b. ibrexafungerp c. flucytosine d. griseofulvin
b. ibrexafungerp
59
antimetabolite drug that inhibits thymidylate synthase a. rezafungin b. ibrexafungerp c. flucytosine d. griseofulvin
c. flucytosine
60
disrupts fungal microtubules a. rezafungin b. ibrexafungerp c. flucytosine d. griseofulvin
d. griseofulvin
61
what is the active metabolite of flucytosine that inactivates thymidylate synthase? a. 5-FU b. 5-FUMP c. 5-UDP d. 5-FdUMP
d. 5-FdUMP (suicide inhibitor)
62
which of the following is TRUE about flucytosine? a. IV only b. removed by kidney c. penetrates poorly into CSF d. nearly always administered with amphotericin B and itraconazole
b. removed by kidney (a. is oral; c. penetrates well; d. is amphotericin B and fluconazole)
63
is griseofulvin fungicidal or fungistatic?
fungistatic
64
antifungal that inhibits leucyl transfer RNA synthetase (LeuRS), thus inhibiting protein synthesis a. tavaborole b. griseofulvin c. flucytosine d. fluconazole
a. tavaborole
65
which chemical element is essential for tavaborole activity? a. chlorine b. aluminum c. selenium d. boron
d. boron
66
tavaborole is used for topical treatment of __________ (nail fungus)
onychomycosis
67
resistance to antifungals: intrinsically resistant to fluconazole; reduced susceptibility to flucytosine and amphotericin B a. Candida krusei b. Candida glabrata c. Aspergillus terreus
a. Candida krusei
68
resistance to antifungals: multiazole, echinocandin, and multidrug resistance a. Candida krusei b. Candida glabrata c. Aspergillus terreus
b. Candida glabrata
69
resistance to antifungals: intrinsically resistant to amphotericin a. Candida krusei b. Candida glabrata c. Aspergillus terreus
c. Aspergillus terreus
70
resistance to antifungals: reduced ergosterol content a. azoles b. polyenes c. echinocandins d. flucytosine
b. polyenes
71
resistance to antifungals: target site mutations; rare a. azoles b. polyenes c. echinocandins d. flucytosine
c. echinocandins
72
resistance to antifungals: cytosine deaminase or UPRT a. azoles b. polyenes c. echinocandins d. flucytosine
d. flucytosine
73
antifungal tx of choice for systemic infections in PREGNANCY
amphotericin B
74
which of the following can be used to treat vaginal yeast infections in PREGNANT patients? a. single dose fluconazole b. single dose itraconazole c. single dose posaconazole d. single dose isavuconazole e. BID fluconazole
a. single dose fluconazole (150 mg)
75
Which of the below choices is the mechanism of action of terbinafine? A. Inhibits the glucan synthase enzyme. B. Inhibits thymidylate synthase. C. Inhibits the 14-alpha-demethylase CYP450. D. Inhibits the squalene epoxidase enzyme
D. Inhibits the squalene epoxidase enzyme
76
Which of the following drugs is an orally available small molecule inhibitor of the fungal glucan synthase enzyme? A. Itraconazole B. Griseofulvin C. Caspofungin D. Ibrexafungerp E. Amphotericin B
D. Ibrexafungerp
77
Which of the following drugs inhibits the leucyl transfer RNA synthetase? A. Tavaborole B. Griseofulvin C. Flucytosine D. Amphotericin B E. Fluconazole
A. Tavaborole
78
Which of the following drugs given by IV, is a synthetically modified fungal compound, and inhibits the fungal beta-glucan synthase enzyme? A. Ibrexafungerp B. Tavaborole C. Griseofulvin D. Itraconazole E. Caspofungin
E. Caspofungin