Brainscape's Knowledge GenomeTM

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


See full index

Pharm I Final Review > Antifungals > Flashcards

Antifungals Flashcards

1
Q

All antifungals target the __________________, except ______________.

A

Cell membrane or cell wall; Griseofulvin and Flucytosine

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

DOC for all systemic fungal infections

A

Amphotericin B (Fungizone)

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

MOA of Amphotericin B

A

Polyene antifungal abx that binds to ergosterol (sterol of the fungal membrane) to form pores in the membrane

FUNGICIDAL because of the pores

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

Broadest spectrum antifungal

A

Amphotericin B

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

Downsides to amphotericin B

A

IV - must be given in hospital
Poor CNS penetration
Excreted slowly by kidney —> VERY nephrotoxic (but that shouldn’t stop you from giving it because systemic fungal infections are life threatening)

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

What is the theory behind amphotericin B toxicity

A

The target of amphotericin B (ergosterol) is structurally quite similar to human cholesterol

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

Infusion related amphotericin B toxicities

A

Chills (give them a blanket, damnit)
Fever, muscle spasms, vomiting headache

May occur with each injection

Can be lessened by slowing infusion rate or decreasing daily dose

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

Cumulative toxicities of Amphotericin B

A

POWERFULLY nephrotoxic agent (azotemia)
Don’t give together with other nephrotoxic meds (ie aminoglycosides)
Renal damage is dose dependent (can be irreversible)
6 weeks to 4 months of treatment

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

Azotemia

A

Azo= nitrogen
The BUN and serum creatinine levels are elevated

Indicative of kidney failure

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

MOA for Flucytosine

A

Metabolic antagonism of fungal DNA and RNA.
Flucytosine is converted to 5-fluorouracil which can then inhibit DNA or RNA synthesis

Has a tendency to disrupt normal flora

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

Antifungals good for CNS penetration

A

Flucytosine (for systemic infections)

Fluconazole

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

DOC for Cryptococcus infections

A

Flucytosine (because it can penetrate the CSF) plus amphotericin B

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

Spectrum for Flucytosine

A 
Lower than Ampho B
Cryptococcus neoformans***
Some Candida
Aspergillosis fumigate
Sporotrichum schenckii
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Flucytosine toxicity

A

Depression of bone marrow (anemia, leukopenia, thrombocytopenia)
May elevate ALT/AST - effect is reversible upon discontinuation
GI disturbances (because it disrupts normal flora)

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

MOA for the Azoles

A

Inhibit the synthesis of ergosterol - leads to the depletion of ergosterol in the cell membrane and accumulation of toxic intermediate sterols, causing increased membrane permeability and inhibition of fungal growth (fungistatic)

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

Ketoconazole

A

Broad antifungal spectrum
Not that great for systemic infections (used pretty much in shampoo now, not really used orally anymore)
Low CNS penetration

17
Q

Toxicity with Ketoconazole

A

POTENT INHIBITOR of P450s —> drug interactions
Gynecomastia and impotence due to inhibition of adrenal and testicular function
Prolonged QT

Contraindicated with acute or chronic hepatic disease

Only considered when you can’t use anything else

18
Q

Fluconazole (Diflucan)

A

Oral and IV
Good CNS penetration - good for fungal meningitis
Good for suppressive and/or prophylactic therapy in HIV+ patients
Less toxic than Ampho B or flucytosine and better tolerated than ketoconazole
Less drug interactions than other azoles (but inhibits CYP2C9)
Headache in 10-15%

19
Q

DOC for Aspergillus

A

Voriconazole + amphotericin B

20
Q

Voriconazole

A

IV and Oral
Modest CSF penetration
DOC for aspergillus with Ampho B

21
Q

Drug interactions for Voriconazole

A 
Metabolized by P450s (2C19>2C9>3A4)
Inhibits P450s (2Cp>3A4>2C19) - inhibits itself but not completely

May see some differences in the populations based on genetics

22
Q

Other voriconazole toxicities

A

Visual impairment (can be reversible) - changes in visual field and acuity, photophobia, and changes in color/light perception

Not well studied - just take them off it

23
Q

Itraconazole

A

Active against many of the same fungi as ketoconazole and fluconazole but has great aspergillus activity (backup DOC behind voriconazole)

Oral, IM

Potent inhibitor of CYP3A4

24
Q

Oral bioavailability of itraconazole

A

Capsules F=40-55% if on empty stomach, 90-100% with meal
Oral solution is 55% when fed and 72% on empty stomach

KEY - two dosage forms should not be used interchangably

25
Q

Isavuconazonium (Cresemba)

A

Azole in terms of MOA (inhibits ergosterol synthesis)

QT and nephrotoxicity

26
Q

Posaconazole (Noxafil)

A

Azole, it’s an new option, but not a lot of data
Lots of drug interactions
Backup for aspergillus and candida

27
Q

MOA for echinocandins

A

Inhibits synthesis of ß(1,3)-D-glucagon (fungal cell wall component not seen in mammals)

Fungicidal

28
Q

Caspofungin

A

Penicillin of the antifungals
Lack of nephrotoxicity and few drug interactions = good treatment option

Good for invasive aspergillosis in refractory patients

The other two echinocandins (Micafungin and Anidulafungin) are very similar but a little less effective

29
Q

Alternate DOC for Aspergillis if Voriconazole + Ampho B doesn’t work

A

Caspofungin

30
Q

DOC for onychomycosis

A

Oral Griseofulvin

May also give a topical, but need the griseofulvin to bind to keratin and take away the infection food source

31
Q

Dermatophytosis

A

Fungal infection that affects different parts of the body, caused by a group of fungi known as dermatophytes.

Fungi invade and feed on keratin

32
Q

Onychomycosis

A

Ringworm of the nail, can be caused by dermatophytes, candida or nondermatophyte molds

33
Q

MOA for griseofulvin

A

Binds to the microtubles of certain fungi and destroys the mitosis spindle structure - fungistatic

Binding to the keratin takes away the food source for the dermatophytes - they can’t infect new cells

34
Q

Griseofulvin toxicity

A

Headache
Some disulfiram-like effects

Contraindicated:
Acute intermittent porphyria
Hepatocellular failure
Pregnancy and men 6 months prior to fathering a child (some teratogenicity)

35
Q

Terbinafine

A

Inhibits ergosterol synthesis like azoles, but causes cell death (azoles do not)

Oral or topical, 2nd drug for onychomycosis

36
Q

DOC for candidal infections

A

Oral nystatin

37
Q

MOA for nystatin

A

Polyene like Ampho B —> pores in cell membrane

Used primarily for candidal infections (orally) or topically for other infections

Pharm I Final Review (8 decks)

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