antifungals- simple Flashcards
which anti fungal is the newest and first to be found in 20 years
echinocandins (1970)
echinocandins target
candida and aspergillus systemic nfection
echinocandins: mode of action
- non competitive inhibition of 1,3,B gluten synthase
- inhibits synthesis of gluten
- causes cells to lose shape and lyse
echinocandins do not lyse filamentous fungi because
e.g. aspergillus have other elements that stabilise the mem
positive of echinocandins
- low toxicity
- no cross resistance
negatives of echinocandins
no activity against C.neoformans. administered via IV- expensive
echinocandins general
- newest
- inhibits synthesis of gluten in cell wall
echinocandins are known as
the penicillins of antifungals since they target cell wall synthesis
5-Flucytosine (5FC) is an
synthetic analogue of cytosine
flu cytosine was first developed as an
anti-cancer drug
flu cytosine only works on
yeast: Candida and C.neoformans
flucytosine: mode of action
- enters the cell via cytosine permeate
- metabolised to 5-flourouracil
- 5 fluorouracil is incorporated into fungal RNA and inhibits synthesis of both DNA and RNA
5-flourouracil
prodrug
negative of flucytosine
resistance is very common
Allyamines are used against
dermatophytes
allyamines work by
inhibiting ergosterol biosynthesis
allyamine: mode of action
inhibits squalene monooxygenase. Squalene accumulates and causes fungi to die- fungicidal
negative of allyamines
-poor activity against candida and aspergillus
azaleas are the
largest group of fungals
azoles are used in
systemic and superficial disease e.g. candidiasis
azoles: mode of action
- inhibits 14 alpha-demethylase by blocking active site
- prevents lanosterol from becoming ergosterol
- fungistatic
azoles preset lanosterols from
becoming ergosterols
imidazole
2 nitrogen- high toxicity and poor speciificity
fluconazole
mad lost of one, but low specificity
-not active against aspergillus
