antifungals- simple

Question 1

which anti fungal is the newest and first to be found in 20 years

Answer 1

echinocandins (1970)

Question 2

echinocandins target

Answer 2

candida and aspergillus systemic nfection

Question 3

echinocandins: mode of action

Answer 3

• non competitive inhibition of 1,3,B gluten synthase
• inhibits synthesis of gluten
• causes cells to lose shape and lyse

Question 4

echinocandins do not lyse filamentous fungi because

Answer 4

e.g. aspergillus have other elements that stabilise the mem

Question 5

positive of echinocandins

Answer 5

• low toxicity

- no cross resistance

Question 6

negatives of echinocandins

Answer 6

no activity against C.neoformans. administered via IV- expensive

Question 7

echinocandins general

Answer 7

• newest

- inhibits synthesis of gluten in cell wall

Question 8

echinocandins are known as

Answer 8

the penicillins of antifungals since they target cell wall synthesis

Question 9

5-Flucytosine (5FC) is an

Answer 9

synthetic analogue of cytosine

Question 10

flu cytosine was first developed as an

Answer 10

anti-cancer drug

Question 11

flu cytosine only works on

Answer 11

yeast: Candida and C.neoformans

Question 12

flucytosine: mode of action

Answer 12

• 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

Question 13

5-flourouracil

Answer 13

prodrug

Question 14

negative of flucytosine

Answer 14

resistance is very common

Question 15

Allyamines are used against

Answer 15

dermatophytes

Question 16

allyamines work by

Answer 16

inhibiting ergosterol biosynthesis

Question 17

allyamine: mode of action

Answer 17

inhibits squalene monooxygenase. Squalene accumulates and causes fungi to die- fungicidal

Question 18

negative of allyamines

Answer 18

-poor activity against candida and aspergillus

Question 19

azaleas are the

Answer 19

largest group of fungals

Question 20

azoles are used in

Answer 20

systemic and superficial disease e.g. candidiasis

Question 21

azoles: mode of action

Answer 21

• inhibits 14 alpha-demethylase by blocking active site
• prevents lanosterol from becoming ergosterol
• fungistatic

Question 22

azoles preset lanosterols from

Answer 22

becoming ergosterols

Question 23

imidazole

Answer 23

2 nitrogen- high toxicity and poor speciificity

Question 24

fluconazole

Answer 24

mad lost of one, but low specificity

-not active against aspergillus

Question 25

negative of azoles

Answer 25

-drug drug interaction

Question 26

drug-drug interaction

Answer 26

specific problem with azoles

- stops the drugs from being meabolised- over-doses

Question 27

both azoles and allyamines

Answer 27

inhibit ergosterol biosynthesis