Antifungal Flashcards
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?
Fungi
What are the two kinds of fungal infections?
1-Superficial
2-Systemic
What are the main 3 mechanisms that anti fungal drugs target?
1-Fungal cell membrane
2-Cell wall synthesis
3-Nucleic acid synthesis (DNA and RNA)
What are the 3 main groups of drugs used to treat systemic fungal infection?
Amphotericin B
Azoles
Echinocandins
Which drug family bind ergosterol in fungal cell membranes?
Polyenes (Amphotericin-B and Nystatin)
*Form pores in the cell membrane
Which drug family inhibits 14-a-sterol demthylase to prevent ergosterol synthesis?
Imidazoles and triazoles
Which drug family inhibits squalene epoxies and prevents ergosterol synthesis?
Allylamines
Which drug family inhibits fungal cell wall synthesis by inhibiting glucan synthesis?
Echinocandins
Which drug is effective against most serious systemic fungal infections(1st line for candidemia), is administered parenterally only, and can cause renal or neurotoxicity?
Amphotericin-B
*Can also be used for aspergillus but is not the drug of choice
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?
Nystatin
What are the two main groups of broad spectrum fungistatic azoles?
Imidazoles (2 nitrogens)
Triazoles (3 nitrogens)
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?
Azoles
*lack selectivity and also inhibit human gonadal and steroid synthesis. Also rarely causes hepatotoxicity
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?
Fluconazole
*widest therapeutic index
Which azole was the first azole used for systemic and topical therapy?
Ketoconazole
Which azole requires lo pH for absorption, does not inhibit steroidogenesis, and is more toxic than fluconazole?
Itraconazole
Which two azoles are used topically only for vulvovaginal candidiasis, oral candidiasis, athletes foot and jock rash?
Clotrimazole and Mitconazole
Which azole is the 1st line treatment for aspergillis?
Vorconizole
Which drug should not be taken with amphotericin B because it reduces the fungicidal action?
Ketoconazole
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?
Flucytosine
Which drugs are the penicillins of the antifungals are fungicidal agains some candida, fungistatic against some aspergillis and is embryo toxic (Cat C)?
Echinocandins
*used against azole resistant candida or 2nd line against refractory aspergillosis
Which echinocandin blocks B-glucan synthase, is used against aspergillis and candida and should be avoided in pregnant patients?
Caspofungin
Which drug is fungistatic by disrupting microtubule function, has a local action increases metabolism of other drugs is teratogenic, carcinogenic and causes severe headaches?
Griseofulvin
Which drug inhibits squalene epoxidase to inhibit ergosterol synthesis, is used to treat dermatophytes, and has replaced griseofulvin for treatment of onychomycosis?
Allylamine antifungals (Terbinafine)
How should normal immune systems vs. immunocompromised be treated for candidiasis?
Normal: topical
Compromised: Sytemic
