DR. MABANAG-ANTIFUNGAL DRUGS PART2 Flashcards

1
Q

● Divided into Triazoles and Imidazoles
● Selective (Triazoles > Imidazoles) affinity (ergo,
toxicity) to fungal than human/ mammalian CY P450
enzyme

A

AZOLES

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2
Q

● Inhibition of fungal cytochrome P450 dependent Lanosterol α-demethylase ⟶ Disruption in the synthesis of Ergosterol ⟶ Damage to the cell membrane, increasing its permeability ⟶ Cell lysis and death.

A

AZOLES

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3
Q

● Many Candida spp, C. neoformans, the endemic
mycoses (blastomycosis, coccidioidomycosis, histoplasmosis), the dermatophytes. Are all susceptible.
● Aspergillus infections - Itraconazole, Posaconazole, Isavuconazole, Voriconazole, the newer Azoles.
● Tx of intrinsically AmB-resistant sp. like P. boydii

A

AZOLES

● Tx of intrinsically AmB-resistant sp. like P. boydii
○ Remember that AmB is inherently resistant to P. boydii, so in these cases we use Azoles.

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4
Q

● 1st oral azole for clinical use
● Less selective to fungal CYP450 compared to
newer Triazoles
● Greater propensity to inhibit mammalian CYP 450

A

Imidazoles:Ketoconazole

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5
Q

● Requires an acidic gastric pH for optimal absorption
○ Potent inhibitor of CYP3A4 (CYP450 enzyme 3A4)
○ potent inhibitor CY3A4 and substrate and inhibitor
for P-gp

A

KETOCONAZOLE

P-gp glycoprotein (P-gp) is an efflux transporter that takes drug molecules from the cell cytoplasm and transports them back into the intestinal lumen for excretion.

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6
Q

KETOCONAZOLE
ADVERSE REACTIONS

A
  1. LIVERTOXICITY
  2. GI STRESS
  3. PRURITUS
    4.INHIBITION OF THE SYNTHESIS OF ADRENAL STEROID AND TESTOSTERONE -SPECIAL EFFECT
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7
Q

● Azole of choice for treatment of dimorphic fungi disease Histoplasma, Blastomyces, Sporothrix
● Activity against Aspergillus sp
● Widely used for treatment of dermatophytoses &
onychomycosis

A

Triazoles:Itraconazole

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8
Q

● DI (drug interaction): decreased bioavailability when taken w/ Rifamycins (Rifampin, Rifabutin,
Rifapentine)
● Does not affect mammalian steroid synthesis like
ketoconazole
● Less effect (vs Ketoconazole) on the metabolism
of concomitant hepatically cleared drugs

A

Triazoles:Itraconazole

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9
Q

Good CSF penetration used for fungal CNS infections
Better GI tolerance
● Kind of safe because of its widest therapeutic index
among azoles → more aggressive dosing in fungal
infections

A

Triazoles:Fluconazole

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10
Q

● Azole of choice in Tx & prophylaxis of
cryptococcal meningitis

● MC DRUG FOR mucocutaneous candidiasis
● Active vs dimorphic fungi limited to coccidioidal meningitis (remove need for intrathecal AmB)

A

Triazoles:Fluconazole

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11
Q

● Written in the clinical practice guidelines for UTI, it is the first-line antifungal for those with urinary
fungal infections.

A

Triazoles:Fluconazole

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12
Q

Clinically relevant CYP3A4 inhibitor - reduce dose
of concomitant meds: CSA, FK 506, HMG-CoA reductase inhibitors (statins)
○ There is drug interaction, in this case, when mixed with Cyclosporin A, FK 506, statins, decreasing the dose of this drug.

A

Triazoles:Voriconazole

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13
Q

Triazoles:Voriconazole
ADVERSE DRUG REACTIONS

A

-RASH
-INC. LIVER ENZYMES
-VISUAL DISTURBANCES (BLURRING OF VISION, VISUAL CHANGES)
-PHOTOSENSITIVITY DERMATITIS

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14
Q

Tx of choice for invasive aspergillosis (less toxic
than AmB) & some environmental molds (Exserohilum rostratum)
○ E. rostratum, which was called “black mold” became an epidemic in 2013 in one state in the USA, and the Tx was voriconazole.

A

VORICONAZOLE

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15
Q

● Broadest spectrum azole
● Activity vs most Candida sp & Aspergillus sp
● 1st azole with significant activity vs
mucormycosis
● Licensed for salvage treatment (Tx) in invasive resistant aspergillosis

A

Triazoles:Posaconazole

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16
Q

● Prophylaxis during leukemia induction chemotherapy, allogeneic bone marrow transplant (BMT) Pts with graft-versus-host disease

A

POSACONAZOLE

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17
Q

● Drug interactions: Do not give with strong 3A4
inhibitors (ex, ritonavir, antiviral for AIDS) or
inducers ( ex, rifampin for TB)

A

Triazoles: Isavuconazole

18
Q

● Spectrum of activity similar to posaconazole
● For invasive aspergillosis & invasive
mucormycosis
● Better tolerated than voriconazole

A

Triazoles: Isavuconazole

19
Q

● Newest class of antifungals
● Large cyclic peptides linked to a Long-Chain Fatty
Acid
● Active vs Candida & Aspergillus
● Inactive vs C. neoformans, agents of mucormycosis
& zygomycosis, and Streptococcus. ● IV only

A

ECHINOCANDINS

20
Q

Micafungin

A

ESOPHAGEAL CANDIDIASIS
CANDIDEMIA
PROPHYLAXIS

21
Q

Anidulafungin(Eraxis)

A

Esophageal candidiasis
CANDIDEMIA

22
Q

● Inhibit the synthesis of ẞ (1-3) glucan of the fungal
cell wall → disruption → cell death

A

ECHINOCANDINS
MOA

23
Q

● disseminated & mucocutaneous candida infections
● (replaced AmB) empiric antifungal Tx in febrile
neutropenia
● Salvage Tx in invasive Aspergillosis after AmB
failure

A

CASPOFUNGIN

24
Q

● mucocutaneous candidiasis
● Candidemia
● Prophylaxis vs Candida infections in BMT

A

MICAFUNGIN

25
Q

● Esophageal candidiasis
● Invasive candidiasis
● candidemia

A

ANIDULAFUNGIN

26
Q

● Derived from a natural form: Penicillium griseofulvum
● Very insoluble
● The only Fungistatic drug so far.
● Only for systemic therapy of dermatophytosis

A

Griseofulvin

27
Q

● MOA: Binds to fungal microtubules to interfere with
mitosis in the replication, not the cell wall.
● Binds to keratin in newly forming skin, protecting
the skin from new infection
-FOR SKIN, HAIR AND NAIL INFECTIONS

A

Griseofulvin

28
Q

Griseofulvin
ADVERSE FFECTS

A

○ Allergic syndrome (like serum sickness)
○ Serious skin reactions
○ Lupus-like syndrome, photosensitivity
○ Hepatotoxicity
○ Drug Interaction with Warfarin,
Phenobarbital

29
Q

● Synthetic allylamine
● Tx of dermatophytes, esp onychomycosis
● KERATOPHILIC
● FUNGICIDAL

A

Terbinafine

30
Q

● MOA: interferes with fungal ergosterol biosynthesis –
inhibits squalene epoxidase → sterol squalene
accumulates (toxic to fungi).

A

Terbinafine

31
Q

● Polyene macrolide like AmB
● Too toxic parenterally. Only used topically
● Oropharyngeal thrush, vaginal candidiasis,
intertriginous candidal infections

A

Nystatin

32
Q

Cream: dermatophytic infections- tinea cruris, tinea
corporis, tinea pedis, athlete’s foot, “buni”, “hadhad”,
and jock itch.

A

TOPICAL AZOLES
Clotrimazole, Miconazole

33
Q
  1. Which of the following statements correctly pairs the antifungal drugs with their likely mechanisms of action?
    a. Griseofulvin - interferes with microtubule function
    b. Flucytosine - inhibits fungal mycolic acid synthesis
    c. Miconazole - inhibits DNA-dependent RNA polymerase
    d. Nystatin - inhibits ergosterol synthesis
A

a. Griseofulvin - interferes with microtubule function

34
Q
  1. All of the following statements correctly pair the antifungal drug with its typical adverse effect, except
    a. Griseofulvin - photosensitivity
    b. Flucytosine - myelosuppression
    c. Nystatin - mental confusion
    d. None of the Above
A

c. Nystatin - mental confusion

35
Q
  1. Which mechanism of antifungal action of azoles?
    of the following statements best explains the
    a. Inhibition of conversion of squalene to lanosterol
    b. Inhibition of fungal mitosis
    c. Inhibition of squalene synthesis
    d. Inhibition of conversion of lanosterol to
    ergosterol
A

d. Inhibition of conversion of lanosterol to
ergosterol

36
Q
  1. Which azole treatment?
    of the following fungal diseases is resistant to
    a. Coccidioidomycosis
    b. Histoplasmosis
    c. Mucormycosis
    d. Aspergillosis
A

c. Mucormycosis

37
Q
  1. Which of the following fungi are sensitive to Griseofulvin?
    a. Candida albicans
    b. Trichophyton rubrum
    c. Pseudomonas aeruginosa
    d. Histoplasma capsulatum
A

b. Trichophyton rubrum

38
Q
  1. Recognized clinical indications for the use of terbinafine include which of the following diseases?
    a. Brucellosis
    b. Toxoplasmosis
    c. Onychomycosis
    d. Histoplasmosis
A

c. Onychomycosis

39
Q
  1. A drug ending in the suffix (azole) is considered a ______.
    a. H
    b. ACE inhibitor
    c. Antifungal
    d. Beta agonist
A

c. Antifungal

40
Q
  1. Azoles are:
    a. Are fungistatic
    b. Inhibits hepatic CYP450 enzymes
    c. Are fungicidal
    d. inhibit cell wall synthesis
A

a. Are fungistatic

41
Q
  1. The following statements are correct for Nystatin, except?
    a. Effective against Candida sp.
    b. Cause gastrointestinal disturbances
    c. Effective against Trichomonas vaginalis
    d. Is fungistatic
A

c. Effective against Trichomonas vaginalis

42
Q
  1. A triazole drug that can be administered orally and IV, excreted mainly unchanged with urine and first-line antifungal for UTI.
    a. Itraconazole
    b. Fluconazole
    c. Isavuconazole
    d. Voriconazole
A

b. Fluconazole