Anti-Fungals Flashcards
How does Echinocandins (caspofungin) work?
Inhibits 1,3-B-glucan synthase which inhibits glucan synthesis which inhibits cell wall synthesis
What makes Echinocandins (caspofungin)? And how is it administered?
- Glarea Lozeyensis
2. IV
What is Echinocandins (caspofungin) used to treat?
Amp-B resistant/invasive Aspergillosis. Esophageal Candidiasis. Pnuemocystis pneumonia
What is the mechanism of action of Griseofluvin?
binds fungal tubulin which interferes with microtubule functioning disrupting cell division and inhibiting mitosis
- targets keratin
What is Griseofluvin made from?
Penicillium Griseofluvin
What is Griseofluvin used to treat?
dermatophytes (taenia infections) especially athlete’s foot
Important points about Griseofluvin
- teratogenic
* increases CYP 450 metabolism- leading to increased effects of other drugs
M.O.A. of polyenes
bind ergosterol creating holes in fungi cell membrane
What is the mechanism of resistance towards polyenes?
Some fungi have decreased amounts of ergosterol in their cell membranes
How are possible side effects of polyenes?
nephrotoxicity and anemia
Key Points about Amphotericin B
“Big gun” and broad spectrum. type of polyene. works by binding to ergosterol causing pores and a leaky membrane (Na+, K+, and CA2+). made from: streptomyces nodosus. IV only- can be very toxic b/c it partially binds to host cholesterol and b/c it’s poorly absorbed from GI
Key points about Nystatin
polyene. works by binding to ergosterol and making pores in cell membrane. Made from: streptomyces noursei. No IV (topical for local infection. or swish and spit for oral thrush)- b/c poor systemic absorption
What is the Anti-metabolite drug and what is its M.O.A.?
- Flucytosine
2. blocks thiamine synthesis thus blocking RNA and DNA synthesis.
Key points about Flucytosine
Oral. used to treat: candida and cryptococcus neoformans ( used with Amp-B to treat cryptococcal meningitis)
- can lead to decreased: WBCs and Platelets. possibly= leukopenia and thrombocytopenia
Azoles M.O.A.
inhibit cytochrome P450 14-alpha demethylase which prevents ergosterol synthesis b/c lanosterol cannot become ergosterol. Thus preventing cell membrane synthesis
*azoles are broad spectrum
Which drugs are Imadizoles (type of azole)? And what is unique structurally?
- ketoconazole and Miconazole
2. 5 membered ring with 2 Nitrogen groups
Which drugs are triazoles (type of azole)? And what is unique structurally?
- Itraconazole, Clotrimazole, fluconazole, and variconazole
2. 5 membered ring with 3 Nitrogen groups
Describe Ketoconazole
broad spectrum imadizole (azole). inhibits ergosterol formation.
decribe miconazole
imadizole (azole) used for dermatophytes. inhibits ergosterol formation.
Describe Itraconazole
broad spectrum triazole (azole) used for candidiasis and systemic infections. inhibits ergosterol formation
Describe Clotrimazole
Triazole (azole) used for topical and vaginal infections. inhibits ergosterol formation
Describe Fluconazole
Triazole (azole). *Has the highest CSF penetration. Use after initial use of Amp-B and flucocytosine. inhibits ergosterol synthesis.
Describe Variconazole
triazole (azole). *has highest oral bioavailability.
Key points about Azoles
includes Imidazoles and Triazoles. largest group of anti-fungals. broad spectrum. can interact with CYP450 (which can impair drug detox. and steroid hormone synthesis and potentiate effects of other drugs). may cause gynecomastia in males.
