Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharm Final antibiotics/fungals > Antifungals > Flashcards

Antifungals Flashcards

1
Q

What are the benefits of fungi

A

source of many medications
penicillin and other beta-lactams
Food-edible mushroom
Insect control-process of competitive exclusion to actively compete for nutrients
Biotech-yeast species used to produce peptide drugs

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

What are the levels of fungal treatment

A

prophylaxis
Empiric
Targeted

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

what is prophylaxis treatment of fungal infections

A

preventive treatment of a specific pathogen in an at risk pt

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

what is empiric treatment for fungal infections

A

treatment as soon as possible or probable fungal infection

based on presence of symptoms consistent with a fungal infection, but no positive culture data

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

what is targeted treatment of fungal infections

A

definitive positive culture data exists allowing for targeted treatment

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

Who is at risk for getting fungal infections

A

Immunosuppressed patients

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

What are big challenges of fungal infections

A 
hard to diagnose
potential toxicity
need for targeted therapy
development of resistance to available agents
limited formulations
aggressiveness of pathogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What drugs make up the Azoles

A

fluconazole
Itraconazole
Voriconazole
Posaconazole

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

what drugs make up the polyenes

A

Nystatin

Amphotericins

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

what is the definition of a fungistatic drug

A

inhibit growth then the immune system can then complete eradication of pathogenic fungi

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

What is the definition of fungicidal drugs

A

kill fungal pathogens. dependent on mechanism of drug and ability to reach adequate concentration at the site of action
preferred treatment in immunocompromised patients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q 
Amphotericin
what class does it belong to?
when was it first made?
how is it administered?
how long is its half-life?
what is the dose adjustment in renal or hepatic impairment?
A 
polyene macrolide antifungal
1950's
only IV form can make oral rinse
15days
no dose adjustment for renal or hepatic impairment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the mechanism of action for amphotericin?

A

binds to and disrupts ergosterol in fungal cell membrane.
Disrupts membranes integrity leading to creation of pores in cell membrane
alteres membrane permeability
This leads to leakage of intracellular components out of the cell and fungal cell death ensues

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

What organism are resistant to Amphotericin

A

Candida lusitainae
Pseudallescheria boydii
Candida krusei (somtimes)

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

what are some adverse effects of amphotericin that are infusion related

A

fever, chills, rigors, hypotension

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

what should you premedicate patients with before getting amphotericin

A

acetaminophen
diphenhydramine
merepridine
hydrocortisone

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

What should you do to test a patients risk/tolerance of ampotericin

A

administer 1mg test dose to asses risk. need to monitor for 15-30min

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

what are adverse effects of amphotericin due to chronic use

A 
Renal toxicity
increased Scr
increased nitrogen comp. like BUN
renal tubular acidosis
K&Mg wasting
hepatic toxicity
increased LFT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the purpose of creating lipid formulations of amphotericin?

A

created to improve tolerability
helps deliver amphotericin to affected tissue
reduce toxicity, but don’t eliminate it
high expense limits use

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

what are the clinical uses of amphotericin

A

reserved for life threatening or refractory conditions

Given IV over 2-6 hours

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

what is the mechanism of action for flucytosine

A

taken up by fungal cells and converted to 5-Fu and then 5-FdUMP and 5-FdUTP
these molecules inhibit fungal DNA and RNA synthesis
has synergistic action with amphotericin

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

what are the adverse effects of flucytosine

A

myelosupression (bonemarrow)

hepatotoxicity

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

what re the clinical uses of flucytosine

A

mostly used to treat crytococcal meningitis
almost always used with other antifungal
rapid development of resistance

24
Q

what makes up the imidazoles (3)

A

ketoconazole
miconazole
clotrimazole

25
Q

what makes up the triazoles

4

A

itraconazole
fluconazole
voriconazole
posaconazole

26
Q

what is the MOA for the azoles

A

inhibit fungal cytochrome p-450 dependent enzyme lanosterol 14 alpha demethylase
reduces formation of ergosterol
considered fungistatic

27
Q

what are the adverse effects of the azoles

A

Gi upset

increased LFTs

28
Q

what are potential drug interactions for the azoles

A

inhibit the human CYP450 enzyme

Major target is CYP450 3A4

29
Q

which has less enzyme selectivity imidazole or the triazoles

A

the imidazoles which is why they have more of an effect on the CYP450 enzymes. So they have more drug interactions

30
Q

What how selective is ketoconazole for the CYP450 enzymes
how is its potentcy compared to new azoles?
what type of infection is it used for?

A

less selective for the fungal CYP450 enzymes
not as potent as the newer azoles
used in topical fungal infection

31
Q

what species for Itraconazole cover?

A

candida and apergillus but have been replaced by voriconazole due to better bioavalibility and penetration of CNS

32
Q

What is Itraconazole used to treat

A

onychomycosis

can also be used in histoplasmosis and blastomycosis

33
Q

What are is fluconazole used for

A

for tx and prophylaxis of coccidiodal and cryptococcal meningitis.
Effective in treatment of canddida
used in pts as prophylaxis in neutropenic patients

34
Q

what species does fluconazole have no effectiveness against?

A

aspergillus

with resistance seen in C. krusei and C. glabrata

35
Q 
Voriconazole
what is it available in?
how is its bioavialbility?
what are the adverse effects?
what do you need to does adjust for?
A

oral tabs, solution, IV form.
excellent bioavail
hepatic tox, rash, visual changes
just need hepatic impairment adjustment

36
Q

How is voriconazoles coverage?

A

broad range of activity
candida, aspergillus, fusarium, scedosporium
used in prophylaxis and invasive fungal infections

37
Q

what organism does posaconazole cover

A

candida, aspergillus, other molds

38
Q

what is posaconazole approved for?

A

prophylaxis of fungal infections in immunosuppressed pts

can also be used for salvage therapy in systemic fungal infections

39
Q

What dosage forms is posaconazole available in

A

oral solution, IV, and tablets

40
Q

What increased the bioavailability of posaconazole?

A

when taken after a full meal or with an acidic carbonate beverage

41
Q

What class of fungi do echinocandins treat

A

candida and apergillus

42
Q

what dose form are echinocandins available in?

A

IV only

43
Q

what is the MOA of echinocandins

A

inhibit beta-1,3-glucan synthase
inhibits creation of component of fungal cell walls
disrupts fungal cell integrity and leads to cell death

44
Q

Echinocandins are fungistatic against which of the two fungi

A

aspergillus

45
Q

echinocandins are fungicidal against which fungi

A

candida

46
Q

what are the adverse effects of echinocandins

A

typically well tolerated
GI effects
flushing reaction if unfused too fast
increased LFT

47
Q

what is echinocandins used for

A

limited to IV

often used in refractory cases or in patients with renal or hepatic impairment

48
Q

what drugs are part of the echinocandins class

A

caspofungin
micafungin
anidulafungin

49
Q

what is caspofungin used to treat

A

disseminated candidiasis, salvage treatment of apergillosis or empiric treatment of possible fungal infection

50
Q

what is micafungin used to treat

A

esophageal candidiasis, candidemia and prophylaxis of candida infections in SCT patients

51
Q

what is andifulafungin used to treat

A

esophageal candidiasis and invasive candidiasis

52
Q

what is griseofulvin used to treat
how is it absorbed
what is its MOA
what is the risk associated with it

A

used to treat fungal skin and nail infection
very poor oral absorption is increased with a high fat meal
Works by binding to keratin in skin and prevents spreading of fungal infection
take weeks to be effective
risk of liver toxicity

53
Q 
what is terbinafine used to treat
what is its MOA
how is it dosed
what is its dose form
what are the risks with this medication
A 
treats dematophytoses and onychomycosis 
interferes with ergosterol synthesis by inhibiting squalene epoxidase
dosed over several months
topical cream or tablets
hepatic tox. with oral tablets
54
Q

what is tolnaftate used to treat

A

used in topical creams and sprays
treats athletes foot and other superficial infections
works by interfering ergosterol synthesis
risk of skin irritation

55
Q

what is nystatin used to treat

what is its dose form

A

active candidiasis
well tolerated topically
powders, cream, vaginal suppositories, oral suspension

56
Q

how do you select antifungal treatment

A

identify patient with or at risk for fungal infection
consider level of treatment (prophylaxis vs empiric vs targeted treatment)
consider fungi involved and severity
select therapy from available agents based on route, spectrum of activity, availability cost and tolerability

Pharm Final antibiotics/fungals (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions