L12 - echinocandins and terbinafine

Question 1

What are the 3 echinocandins?

Answer 1

Caspofungin
Anidulafungin
Micafungin

Question 2

How are echinocandins administered?

Answer 2

IV as too big for oral

Question 3

What can caspofungin treat?

Answer 3

invasive candidosis
aspergillosis
empiric therapy

Question 4

What can Anidulafungin treat?

Answer 4

Invasive candidosis

Question 5

What can Micafungin treat?

Answer 5

Invasive candidosis
oesophageal candidosis
candidosis prophylaxis

Question 6

What is used to treat aspergillosis if ambisome does not work?

Answer 6

Caspofungin

Question 7

What do echinocandins inhibit?

Answer 7

glucan synthase

Question 8

Mode of action of echinocandins?

Answer 8

bind to Fks1p subunit - block beta1,3-D-glucan synthesis

Question 9

What are echinocandins not active against?

Answer 9

Cryptococcus
Mucoraceous moulds
Dimorphic fungi

Question 10

Are echinocandins fungistatic or fungicidal?

Answer 10

mainly fungistatic

Question 11

What causes less toxicity, caspofungin or amphotericin B, when treating candidaemia?

Answer 11

Caspofungin (slightly)

Question 12

What is superior when treating candidaemia , andulafungin or fluconazole?

Answer 12

andulafungin

Question 13

What is superior when treating candidaemia, Micafungin or Ambisome?

Answer 13

similar

but micafungin has FEWER SIDE EFFECTS

Question 14

Toxicity associated with caspofungin?

Answer 14

hypokalemia
fever
deranged liver function

Question 15

Toxicity associated with andulafungin?

Answer 15

headache
nausea
deranged liver function

Question 16

Toxicity associated with Micafungin?

Answer 16

headache

deranged liver function

Question 17

Do echinocandins undergo hepatic metabolism?

Answer 17

some metabolism,

but NOT through CYP450

Question 18

Does caspofungin interact with other durgs?

Answer 18

some immunosuppressants
child steroids
some anti-microbials

Question 19

Does andulafungin interact with other drugs?

Answer 19

none known

Question 20

Does micafungin interact with other drugs?

Answer 20

some immunosuppressant

Question 21

How can Candida albicans be resistant to Echinocandins?

Answer 21

mutations in gene for FSK1 of beta 1-3 glucan synthase complex

codon 645 serine is mutated

Question 22

What other fungi are resistant to echinocandins?

Answer 22

C. glabrata

Cryptococcus?

Question 23

What is the paradoxical effect seen in echinocandins?

Answer 23

at high conc., anti fungal stops working - forces cells to respond rapidly and bypasses effects of drugs

Question 24

How does the paraodoxical effect occur in echinocandins?

Answer 24

up regulation of chitin biosynthesis

up regulation of cell wall integrity pathway

Question 25

Is there an upregulation of chitin in response to caspofungin?

Answer 25

yes

Question 26

What class of drug is Terbinafine?

Answer 26

allylamine

Question 27

What is the mode of action of terbinafine?

Answer 27

inhibition of squalene epoxidase - usually catalyses step in ergosterol synthetic pathway

Question 28

What can terbinafine be used against?

Answer 28

moulds - dermatophytes, dematiacous fungi, apergillus-like moulds some yeasts

Question 29

What are the formulations of terbinafine?

Answer 29

Tablets Gel/ cream Spray

Question 30

What are the indications of Terbinafine?

Answer 30

dermatophyte infections of skin/nail yeast skin infection

Question 31

What is more effective at pulse therapy - terbinafine or itraconazole?

Answer 31

terbinafine

Question 32

Does terbinafine bind to proteins?

Answer 32

yes, >90%

Question 33

What is Terbinafine metabolised by?

Answer 33

CYP enzymes

Question 34

Toxicity of terbinafine?

Answer 34

occasional liver dysfunction altered taste perception

Question 35

drug interactions of terbinafine?

Answer 35

lots due to metabolism by CYP450 similar to azoles but other antifungals and anti-depressants too

Question 36

Is there resistance to terbinafine?

Answer 36

rare substitution mutation in squalene epoxidase gene in Trichophyton rubrum also issues with T. interdigitale

Question 37

What is Ibrexfungerp?

Answer 37

NEW ANTI-FUNGAL Terpenoid glycoside inhibitor

Question 38

What is Ibrexafungerp active against?

Answer 38

Candida | Aspergillus