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Pharmacology Block 3 > Antifungals > Flashcards

Flashcards in Antifungals Deck (14):
1

Amphotericin B:

MOA: Binds ergosterol in fungal membranes producing membrane instability/leakage.

Uses: -Effective for most serious systemic mycoses.
-Total cumulative dose is important for renal toxicity.
-Available topically for cutaneous or mucosal Candida.

SEs:
-Nonpermanent nephrotoxicity.
-Permanent renal damage – related to total drug dose.
-Reversible hypochromic, normocytic anemia.
-Fever, nausea, vomiting, headache, chills.

2

Flucytosine:

MOA: Fungal deaminase converts the drug to 5-FU, which blocks nucleic acid synthesis.

Uses: -Serious infections due to Candida, Cryptococcus.
-Used in conjunction with amphotericin; permits reduction of amphotericin dosage.

SEs:
-Potentially fatal leukopenia, thrombocytopenia.
-Use extreme caution in those with renal insufficiency or bone marrow depression.
-Nausea, vomiting, diarrhea, enterocolitis.

3

Fluconazole:

MOA: Inhibit a fungal cytochrome P450, which blocks the synthesis of ergosterol.

Uses: -Fungal meningitis (great CNS penetration).
-Some Candida.
-Mucous membrane Candida infections.

SEs:
-*Contraindicated with drugs that inhibit CYP3A4.
-Hepatotoxicity – discontinue if signs of liver dysfunction appear.

4

Itraconazole:

MOA: Inhibit a fungal cytochrome P450, which blocks the synthesis of ergosterol.

Uses: -Blastomyces, histoplasma.
-Broader Candida coverage.
-NO CNS penetration.
-Liver metabolism.
-Oropharyngeal and esophageal candidiasis.
-Oral therapy for toenail infections

SEs:
-*Contraindicated with drugs that inhibit CYP3A4.
-Hepatotoxicity – discontinue if signs of liver dysfunction appear.

5

Voriconazole:

MOA: Inhibit a fungal cytochrome P450, which blocks the synthesis of ergosterol.

Uses: -Invasive Aspergillus (only one that’s better than amphotericin).
-Even broader Candida coverage.
-Liver metabolism.

SEs:
-*Contraindicated with drugs that inhibit CYP3A4.
-Hepatotoxicity – discontinue if signs of liver dysfunction appear.
-Visual disturbances, photosensitive rash.

6

Caspofungin:

MOA: Inhibits fungal cell wall synthesis by blocking synthesis of B-glucan.

Uses: -Candida
-Treatment of invasive Aspergillus.

SEs: generally well-tolerated.

7

Miconazole:

MOA: Inhibit a fungal cytochrome P450, which blocks the synthesis of ergosterol.

Uses: -Mucous membrane Candida infections.
-Treatment of common skin and hair infections.

8

Clotrimazole:

MOA: Inhibit a fungal cytochrome P450, which blocks the synthesis of ergosterol.

Uses: -Mucous membrane Candida infections.
-Treatment of common skin and hair infections.

SEs: -Topical form usually fine.
-Oral form may cause hepatotoxicity.

9

Nystatin:

MOA: Binds ergosterol in fungal membranes producing membrane instability/leakage.

Uses: -Almost exclusively for Candida

SEs: Orally: GI upset, bad taste.

10

Natamycin:

MOA: Binds ergosterol in fungal membranes producing membrane instability/leakage.

Uses: -For fungal eye infections

SEs: -Toxicity: conjunctival chemosis and hyperemia.

11

Tolnaftate:

Uses: -Treatment of common skin and hair infections.

12

Terbinafine:

MOA: Causes the accumulation of squalene, which damages fungal cell membranes.

Uses: -Treatment of common skin and hair infections.
-Oral prep for more severe dermatophyte infections.

SEs: Diarrhea, dyspepsia, abdominal pain.
Inhibits CYP2D6.

13

Ciclopirox:

-Used topically for fungal nail infections.
-Will not kill fungus, but prevents spread to new nail as it grows in (takes a while).

14

Griseofulvin:

MOA: Interferes with microtubule function; arrests fungi in metaphase of mitosis.

Uses: -For recalcitrant dermatophyte infections that are beyond the scope of topical therapy.
-Recommended therapy for children with tinea capitis.

SEs: -Contraindicated in those with porphyria and advanced liver disease.
-Increased metabolism of other drugs.
-Use with caution in those with penicillin allergies.