Antifungals

Question 1

Amphotericin B

Answer 1

Binds ergosterol (unique to fungi). Forms membrane pores that allow leakage of electrolytes.
Serious, systemic mycoses. Cryptococcus (amphotericin B ± flucytosine), Blastomyces, Coccidioides, Histoplasma, Candida, Mucor. Intrathecally for fungal meningitis.
Fever/chills (shake and bake), hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis. Supplement K and Mg because of altered renal tubule permeability. Hydration decreases nephrotoxicity. Liposomal amphotericin decreases toxicity.

Question 2

Nystatin

Answer 2

Binds ergosterol (unique to fungi). Forms membrane pores that allow leakage of electrolytes. Too toxic for systemic use, topical only.
Oral candidiasis (thrush), diaper rash, vaginal candidiasis.

Question 3

Fluconazole

Answer 3

Azole.
Inhibits fugal sterol (ergosterol) synthesis by inhibiting cytochrome P-450 enzyme that converts lanosterol to ergosterol.
Local and less serious systemic mycoses. Chronic suppression of cryptococcal meningitis in AIDS patients and candidal infections of all types.
Liver dysfunction (inhibits cytochrome P-450).

Question 4

Ketoconazole

Answer 4

Azole.
Inhibits fugal sterol (ergosterol) synthesis by inhibiting cytochrome P-450 enzyme that converts lanosterol to ergosterol.
Local and less serious systemic mycoses.
Liver dysfunction (inhibits cytochrome P-450), inhibits testosterone synthesis (gynecomastia).

Question 5

Clotrimazole

Answer 5

Azole.
Inhibits fugal sterol (ergosterol) synthesis by inhibiting cytochrome P-450 enzyme that converts lanosterol to ergosterol.
Local and less serious systemic mycoses. Topical fungal infections.
Liver dysfunction (inhibits cytochrome P-450).

Question 6

Miconazole

Answer 6

Azole.
Inhibits fugal sterol (ergosterol) synthesis by inhibiting cytochrome P-450 enzyme that converts lanosterol to ergosterol.
Local and less serious systemic mycoses. Topical fungal infections.
Liver dysfunction (inhibits cytochrome P-450).

Question 7

Itraconazole

Answer 7

Azole.
Inhibits fugal sterol (ergosterol) synthesis by inhibiting cytochrome P-450 enzyme that converts lanosterol to ergosterol.
Local and less serious systemic mycoses. Blastomyces, Coccidioides, Histoplasma.
Liver dysfunction (inhibits cytochrome P-450).

Question 8

Voriconazole

Answer 8

Azole.
Inhibits fugal sterol (ergosterol) synthesis by inhibiting cytochrome P-450 enzyme that converts lanosterol to ergosterol.
Local and less serious systemic mycoses.
Liver dysfunction (inhibits cytochrome P-450).

Question 9

Flucytosine

Answer 9

Inhibits DNA and RNA biosynthesis by conversion to 5-fluorouracil by cytosine deaminase.
Systemic fungal infections (especially meningitis caused by Cryptococcus) in combination with Amphotericin B.
Bone marrow suppression.

Question 10

Caspofungin

Answer 10

Echinocandin.
Inhibits cell wall synthesis by inhibiting synthesis of β-glucan.
Invasive aspergillosis, Candida.
GI upset, flushing (histamine release).

Question 11

Micafungin

Answer 11

Echinocandin.
Inhibits cell wall synthesis by inhibiting synthesis of β-glucan.
Invasive aspergillosis, Candida.
GI upset, flushing (histamine release).

Question 12

Anidulafungin

Answer 12

Echinocandin.
Inhibits cell wall synthesis by inhibiting synthesis of β-glucan.
Invasive aspergillosis, Candida.
GI upset, flushing (histamine release).

Question 13

Terbinafine

Answer 13

Inhibits fungal enzyme squalene epoxidase.
Dermatophytoses (especially onychomycosis).
GI upset, headaches, hepatotoxicity, taste disturbance.

Question 14

Griseofulvin

Answer 14

Interferes with microtubule formation, disrupts mitosis. Deposits in keratin-containing tissues (nails).
Oral treatment of superficial infections, inhibits growth of dermatophytes (tinea, ringworm).
Teratogenic, carcinogenic, confusion, headaches, induces P-450 and warfarin metabolism.