Antifungal

Question 1

What organisms live as saprobes or parasites, have a rigid cell wall made of chitin and have ergosterol in their cell membranes instead of cholesterol?

Answer 1

Fungi

Question 2

What are the two kinds of fungal infections?

Answer 2

1-Superficial

2-Systemic

Question 3

What are the main 3 mechanisms that anti fungal drugs target?

Answer 3

1-Fungal cell membrane
2-Cell wall synthesis
3-Nucleic acid synthesis (DNA and RNA)

Question 4

What are the 3 main groups of drugs used to treat systemic fungal infection?

Answer 4

Amphotericin B
Azoles
Echinocandins

Question 5

Which drug family bind ergosterol in fungal cell membranes?

Answer 5

Polyenes (Amphotericin-B and Nystatin)

*Form pores in the cell membrane

Question 6

Which drug family inhibits 14-a-sterol demthylase to prevent ergosterol synthesis?

Answer 6

Imidazoles and triazoles

Question 7

Which drug family inhibits squalene epoxies and prevents ergosterol synthesis?

Answer 7

Allylamines

Question 8

Which drug family inhibits fungal cell wall synthesis by inhibiting glucan synthesis?

Answer 8

Echinocandins

Question 9

Which drug is effective against most serious systemic fungal infections(1st line for candidemia), is administered parenterally only, and can cause renal or neurotoxicity?

Answer 9

Amphotericin-B

*Can also be used for aspergillus but is not the drug of choice

Question 10

Which drug is similar to amphotericin B but is only used topically because it has a high toxicity, is used for oral, esophageal or vaginal candidiasis and can have a disulfiram like reaction?

Answer 10

Nystatin

Question 11

What are the two main groups of broad spectrum fungistatic azoles?

Answer 11

Imidazoles (2 nitrogens)

Triazoles (3 nitrogens)

Question 12

Which group of antifungals increase membrane fluiditiy by inhibiting ergosterol synthesis, are used topically or systemically and are contraindicated for pregnant, lactating or hepatic dysfunction patients?

Answer 12

Azoles

*lack selectivity and also inhibit human gonadal and steroid synthesis. Also rarely causes hepatotoxicity

Question 13

Which azole is the most commonly prescribed systemic anti fungal, is the drug of choice for candidiasis, is effective agains fungal cryptococcal meningitis in AIDs and is highly teratogenic?

Answer 13

Fluconazole

*widest therapeutic index

Question 14

Which azole was the first azole used for systemic and topical therapy?

Answer 14

Ketoconazole

Question 15

Which azole requires lo pH for absorption, does not inhibit steroidogenesis, and is more toxic than fluconazole?

Answer 15

Itraconazole

Question 16

Which two azoles are used topically only for vulvovaginal candidiasis, oral candidiasis, athletes foot and jock rash?

Answer 16

Clotrimazole and Mitconazole

Question 17

Which azole is the 1st line treatment for aspergillis?

Answer 17

Vorconizole

Question 18

Which drug should not be taken with amphotericin B because it reduces the fungicidal action?

Answer 18

Ketoconazole

Question 19

Which drug inhibits both DNA and RNA synthesis, is used for systemic fungal infections, is synergistic with amphotericin B for cryptococcal meningitis but may cause bone marrow suppression?

Answer 19

Flucytosine

Question 20

Which drugs are the penicillins of the antifungals are fungicidal agains some candida, fungistatic against some aspergillis and is embryo toxic (Cat C)?

Answer 20

Echinocandins

*used against azole resistant candida or 2nd line against refractory aspergillosis

Question 21

Which echinocandin blocks B-glucan synthase, is used against aspergillis and candida and should be avoided in pregnant patients?

Answer 21

Caspofungin

Question 22

Which drug is fungistatic by disrupting microtubule function, has a local action increases metabolism of other drugs is teratogenic, carcinogenic and causes severe headaches?

Answer 22

Griseofulvin

Question 23

Which drug inhibits squalene epoxidase to inhibit ergosterol synthesis, is used to treat dermatophytes, and has replaced griseofulvin for treatment of onychomycosis?

Answer 23

Allylamine antifungals (Terbinafine)

Question 24

How should normal immune systems vs. immunocompromised be treated for candidiasis?

Answer 24

Normal: topical
Compromised: Sytemic