Antifungals Flashcards
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.
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.
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.
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.
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.
Caspofungin:
MOA: Inhibits fungal cell wall synthesis by blocking synthesis of B-glucan.
Uses: -Candida
-Treatment of invasive Aspergillus.
SEs: generally well-tolerated.
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.
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.
Nystatin:
MOA: Binds ergosterol in fungal membranes producing membrane instability/leakage.
Uses: -Almost exclusively for Candida
SEs: Orally: GI upset, bad taste.
Natamycin:
MOA: Binds ergosterol in fungal membranes producing membrane instability/leakage.
Uses: -For fungal eye infections
SEs: -Toxicity: conjunctival chemosis and hyperemia.
Tolnaftate:
Uses: -Treatment of common skin and hair infections.
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.
Ciclopirox:
- Used topically for fungal nail infections.
- Will not kill fungus, but prevents spread to new nail as it grows in (takes a while).
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.
