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40 Cards in this Set

  • Front
  • Back
name five classes of drugs that work on fungal cell membranes
1. polyenes
2. azoles
3. allylamines
4. pyridones
5. echinocandins
almost every polyene contains a __ moiety
mycosamine
name six fungi susceptible to the polyenes
histo
crypto
blasto
coccidiodies
candida
sporothrix
polyene MOA
bind sterols in both serum and cell membranes -> membrane structure perturbed -> leakage of cell components and altered membrane transport
polyene method of selectivity
principal fungal membrane sterol is ergosterol, in us it is cholesterol
name the two most frequently used polyenes
Nystatin
Amphotericin B
if nystatin is virtually insoluble, what do we use it for?
superficial infections and infections of GI tract (GI fungi? how on earth do you diagnose that?)
which is more potent, amphotericin B or Nystatin,
amphotericin B- soluble enough for IV admin
what are liposomal preparations of amphotericin B
combine liposomal amphotericin B with amphotericin B lipid complex - give larger volumes of distribution and decreased renal toxicity (good but expensive)
clotrimazole
fluconazole
itraconazole
ketoconazole
miconazole
sertaconazole
ticonazole
voriconazole
gluconazole
the azoles- imidazole and triazole antifungals
azole MOA
inhibits 14-alpha-demethylase (a P450 involved in ergosterol biosynthesis) -> makes membranes w/ altered permeability
azole method of selectivity
fungal sterol biosynthesis is more sensitive to inhibition than mammalian synthesis
miconazole is given ...
ketoconazole, fluconazole, itraconazole are given...
topical
orally
___ can be used for oral treatment of infections of nails and is the azole drug of choice for tx of dermatophytoses and onychomycosis
itraconazole
___ is drug of chice for treatment of invasive aspergillosis
voriconazole
___ has good CNS penetration and is superior for the tx of AIDS associated cryptococcal meningitis
gluconazole
what is the advantage of using the azoles over amphotericin B
they are metabolized primarily by liver- can be given to patients w/ impaired renal function
do azoles induce or inhibit CYP3A4
inhibit, just like the polyenes
___ inhibits other mammalian P450s and reduces adrenal and gonadal steroid biosynthesis
ketoconazole
___ can precipitate CHF in some patients
itraconazole
method of resistance to azoles
1. overproductions of 14-alpha-demethylase
2. overexpression of MDR-like efflux pump
name three allylamines
naftafine
terbinafine
butenafine
allylamine MOA
inhibits fungal squalene epoxidase
allylamines when used topically are effective in tx of...
when used orally...
tinea infection

cutaneous tinea infections, cutaneous candidiasis
___ is a pyridone antifungal agent that inhbits uptake of essential extracellular nutrients
ciclopirox olamine
only approved drug for topical tx of dermatophyte infection of hair and nails
ciclopirox olamine
___ is an echinocandin noncompetititve inhibitor of beta-(1,3)-glucan synthase
caspofungin
___ is used for treatment of invasive aspergillosis in patients refractory to amphotericin B and for esophageal candidiasis
caspofungin
___ is a cytosine analogue substituted in the 5-position of the pyrimidine ring with fluorine and inhibits fungal nucleic acid synthesis
flucytosine
when is flucytosine used
only in combo w/ amphotericin B because resistance occurs frequently
flucytosine MOA
metabolized by cytosine deaminase ->
5-fluorouracil ->
incorporated into fungal RNA

also, FdUMP inhibits thymidylate synthetase -> blocks de novo synthesis of dTMP
flucytosine method of selectivity
compared to fungal deaminase activity, mammalian activity is very low
flucytosine route of admin
orally
name a fungal mitotic inhibitor
griseofulvin
___ is an insolube compound effective in tx of fungal infection of skin, hair, nails caused by epidermophyton, micosprum and trichophyton
griseofulvin
griseofulvin is ineffective against...
candida
griseofulvin MOA
disrupts microtubule formation
griseofulvin method of selectivity
unknown
external infections are most responsive to __ therapy with griseofulvin, but...
oral
but...it isn't a major metabolite- it must be converted to 6-demethylgriseofulvin and is more absorbed if taken with a fatty meal
(take griseofulvin and eat some Greasy pizza)
griseofulvin absorption is inhibited from the gut by...
barbituates