Antifungal Drugs Flashcards Preview

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Flashcards in Antifungal Drugs Deck (55)
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1
Q

What are the antifungals

A
Amphoteracin B
Flucytosine
Ketoconazole
Miconazole 
Clotrimazole
Fluconazole  
Itraconazole
Voriconazole 
Posaconazole
Caspofungin
Griseofulvin
Terbinafine
Nystatin
2
Q

What is Amphoteracin B

A

Polyene ABX

3
Q

How does Amphoteracin work

A

Binds ergosterol

Pores in cell membrane

4
Q

What does Amphoteracin B work on

A

Yeast and Molds

5
Q

When do you give Amphoteracin B

A

Life-threatening infections
Initial therapy to reduce viral load
Continue on azole

6
Q

What is the preferred antifungal for deep fungal infection during pregnancy

A

Amphoteracin B

7
Q

Amphoteracin B administration

A

IV

Intrathecal if meningeal disease

8
Q

Amphoteracin B AE

A

Renal toxicity
Anemia - Decreased EPO
Seizures in intrathecal
Fever, chills, muscle spasms, HA, hypotension

9
Q

How do you reduce nehphrotoxicity with Amphoteracin B

A

Lipid colloid

10
Q

How does Flucytosine work

A
Enters cell via cytosine permease
Converted to 5-FU then 5-FdUMP/5-FUMP
Inhibits Thymidylate Synthase
Incorporates into protein
DNA and Protein synthesis inhibition
11
Q

What is Flucytosine used for

A

Candida

Cryptococcal

12
Q

How does Flucytosine cause BM toxicity

A

Formation of 5-FU from gut flora

13
Q

Synergistic with Flucytosine

A

Amphoteracin B

14
Q

Imidazoles

A

Ketoconazole
Miconazole
Clotrimazole

15
Q

How do the azoles work

A

Inhibit 14-alpha sterol demethylase
Blocking conversion of lanosterol to ergosterol
Membrane disruption

16
Q

What are the triazoles

A

Fluconazole
Itraconazole
Voriconazole
Posaconazole

17
Q

Which azoles are less specific for fungal CYP

A

Imidazoles

18
Q

DOC candida and most coccidioides

A

Fluconazole

19
Q

Inhibitor of 3A4

A

Azoles
Fluco - moderate but strong 2C9
Voriconazole - also 2C9, 2C19

20
Q

What do imidazoles potentiate the toxicity of

A

Warfarin

Cyclosporine

21
Q

Since it has a narrow spectrum what should imidazoles be used for

A

Superficial mycoses

22
Q

Why can PPIs and H2 blockers interfere with Ketoconazole absorption

A

Best absorbed at low pH

23
Q

Imidazole AE

A

Gynecomastia
Menstrual irregularities
Decreased plasma cortisol (inhibition of adrenal steroid synthesis)

24
Q

Which imidazoles are available as topical OTC

A

Clotrimazole

Miconazole

25
Q

Maintenance therapy or prophylaxis for cryptococcal meningitis

A

Fluconazole (after Amphoteracin B initial)

26
Q

Which azoles can penetrate CSF

A

Fluconazole

27
Q

What is the only azole that has renal excretion

A

Fluconazole

28
Q

What can Fluconazole increase the plasma levels of

A

Phenytoin
Zidovudine
Warfarin

29
Q

What is Fluconazole not good for

A

Aspergillus and other filamentous fungi

30
Q

What is the absorption of Itraconazole reduced by

A

H2 blockers and PPIs

31
Q

What is Itra/Vori/Posaconazole given for

A
Aspergillus
Blastomycoses
Sporothrix
Histoplasma
Dermatophytosis
Onychomycosis
32
Q

When can Itraconazole cause fatal arrhythmias

A

When given with Cisapride or Quinidine

33
Q

DOC invasive aspergillosis

A

Voriconazole

34
Q

Voriconazole AE

A

Transient visual disturbance

35
Q

Good for Mucor

A

Posaconazole

36
Q

How does Caspofungin act

A

Inhibits beta (1.3) glucan synthesis in cell wall

37
Q

What does Caspofungin act on

A

Candida

Aspergillus

38
Q

What is Caspofungin ineffective against

A

C. neoformans

39
Q

Structure of Caspofungin

A

Large cyclic peptide linked to long chain FA

40
Q

How does Griseofulvin work

A

Disrupt mitotic spindle

41
Q

What is Griseofulvin for

A

Dermatophysis (skin, hair, nails)

42
Q

How do you improve Griseofulvin absorption

A

Give with fatty food

43
Q

Induces P450

A

Griseofulvin

44
Q

Action of Terbinafine

A

Inhibitis Squalene Epoxidase

No ergosterol and toxic levels of squalene

45
Q

Most effective against Onychomycosis

A

Terbinafine

46
Q

Is an Allylamine

A

Terbinafine

47
Q

Accumulates in keratin

A

Terbinafine

48
Q

No effect on P450

A

Terbinafine

49
Q

Terbinafine AE

A

GI upset

Rash, HA, taste disturbance

50
Q

Topical cream use of Terbinafine

A

Tinea cruris, corporis

51
Q

What is Nystatin

A

Polyene macrolide

52
Q

What is Nystatin similar to

A

Amphoteracin B (structure and action)

53
Q

What is the only use of Nystatin

A

Candidiasis

Cutaneous oral/vaginal administration

54
Q

Why isn’t Nystatin given IV

A

Too toxic

55
Q

What else can you give for cutaneous candidiasis

A

Topical Amphoteracin B