DD- Fungal Infections/Rx Flashcards Preview

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Flashcards in DD- Fungal Infections/Rx Deck (16)
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1
Q

Factors that allow overgrowth of opportunistic organisms

A

Alteration in oral flora
Immunosuppression
Systemic diseases

2
Q

Binds ergosterol in fungal membrane
opens pores
leakage of cellular constituents
cell death [fungicidal]

A

Amphotericin B - Mechanism of Action

3
Q

Similar mechanism to Amphotericin B - toxicity limits systemic use

No appreciable absorption from GI tract

Safe and effective for topical treatment of candidal infections of skin, mucous membranes, and GI tract

A

Nystatin

4
Q
  • Myelosuppression with chemotherapy agents
  • Long-term use of steroid anti-inflammatory agents
  • Inhaled steroids use in asthma
A

Can cause immunosupression

5
Q

Deep candidiasis

Aspergillosis

Mucormycosis

Cryptococcosis

Extracutaneous sporotrichosis

A

life-threatening systemic fungal infections (esp. in immunosuppressed patients)

6
Q

Inhibits the synthesis of β (1,3)-D-glucan - essential component of fungal cell walls. disruption of cell wall

Higher level of selective toxicity due to absence of these enzymes in mammalian cells

A

Echinocandins - Micafungin

7
Q

Drug of choice for nearly all life-threatening systemic fungal infections (esp. in immunosuppressed patients)

A

Amphotericin B - Clinical Uses

8
Q
  • AIDS, diabetes
  • Long-term xerostomia (anticholinergic agents)
  • Adrenal suppression (steroid anti-inflammatory agents)
  • Anemia
A

Systemic diseases examples

9
Q

Selective inhibition of fungal cytochrome P450 (14α-demethylase)  ↓ ergosterol synthesis  fungistatic-cidal

Greater selectivity for fungal vs mammalian cytochrome

A

Triazoles

Fluconazole - Itraconazole

10
Q

Inhibits P450-dependent enzyme (14α-demethylase) resulting in decreased levels of ergosterol

Disruption in synthesis of cell membrane sterols, alterations in membrane permeability

Fungistatic / fungicidal depending on concentration

A

Imidazoles

Ketoconazole - Clotrimazole - Miconazole

11
Q

Inhibits squalene oxidase, dec ergosterol synthesis (plus accumulation of squalene is toxic), fungicidal

Concentrates in keratin (like griseofulvin)

A

Terbinafine

12
Q

Converted in fungal cell into 5-fluorouracil (via cytosine deaminase)

5-FU interferes with DNA synthesis, cell death

High selective toxicity - host cells lack deaminase

Resistance occurs in fungi that lack cytosine deaminase

A

Flucytosine

13
Q

Binds to microtubules inhibiting fungal mitosis - interferes with processing of new cell wall components - fungistatic

A

Griseofulvin

14
Q

Inhibits protein and nucleic acid synthesis

Effective against wide variety of protozoa (concentrated in organisms)

A

Pentamidine

15
Q

Dermatophytes

A

Infections deeper in the epidermis and its integuments - hair and nails

16
Q

Dermatophytes Rx

A

Generally conservative with use of topical antifungal agents (clotrimazole, miconazole, terbinafine)