Antifungals

Question 1

8 examples of azoles and their mechanism

Answer 1

Inhibit cytochrome P450-dependent synthesis of ergosterol in fungal cells

Clotrimazole
Climbaxole
Eniloconazole
Fluconazole
Itraconazole
Ketoconazole
Micronazole
Posaconazole

Question 2

What is ergosterol

Answer 2

A compound found present in ergot and many other fungi
Steroid alcohol, converted to vitamin D2 when irradiated with ultraviolet light

Question 3

mechanism and example of allyamines

Answer 3

inhibits synthesis of ergosterol in fungal cells via inhibiting an enzyme (squalene epoxidase)

terbinafine

Question 4

mechanism and 2 examples of polyenes

Answer 4

Binds to sterols (ergosterol) in fungal cell membranes

Amphotericin B
Nystatin

Question 5

Mechanism and example of Pyrimidine Analogues

Answer 5

Converted by the fungal cells to 5-fluorocil

5-fluorocytosine

Question 6

chlorhexidine

Answer 6

Antiseptic, not specific to fungal
used topically for malessieza and dermatophytosis infections

Question 7

F10

Answer 7

Disinfectant used to treat fungal dermatitis in reptiles

Question 8

3 Cellular toxin products with antifungal activity

Answer 8

NOT specific to fungi

Silver sulfadiazine- releases silver in concentrations that are toxic to bacteria and yeasts

Chlorhexidine- antiseptic, binds to skin and forms a protective layer

Virkon- disinfectant- pre-oxygen compound that oxidised sulphur bonds in proteins and enzymes disrupting the function of the cell membrane

Question 9

Antifungals used for Otitis externa in cats and dogs

Answer 9

!Nystatin
!Miconazole
!Clotrimazole- off licence in cats
Posaconazole- off licence in cats
!Terbinafine- NOT CATS
THE ABOVE PRODUCTS ALSO CONTAIN STEROID AND ANTIBIOTICS

Silver sulfadiazine- off licence for Malessezia/pseudomonas resistant infections

Question 10

Antifungals used for Malessezia skin infections in cats and dogs

Answer 10

!Miconazole- shampoo
Climbazole- wipes
itraconazole- off licence in dogs; oral systemic treatment
Ketoconazole-DO NOT USE IN CATS, oral, shampoo or skin spray
Chlorhexidine- shampoo/foam/spray/otic solution/wipes
(Terbinafine- off licence; oral/gel/cream/spray- RARELY USED)

Question 11

antifungals used for ringworm (dermatophytosis), cats and dogs

Answer 11

!Itraconazole-oral, systemic treatment; off licence in dogs
!ketoconazole-oral,systemic; DO NOT USE IN CATS
!enilconazole- skin rinse; off licence in cats
!Miconazole- adjunctive, shampoo
!chlorhexidine- shampoo/foam/spray/otic solution/wipes; synergistic with miconazole, ineffective alone
Clotrimazole- cream, adjunctive treatment; off licence
(Terbinafine)- RARE
(Fluconazole)- RARE

Question 12

Antifungals used for systemic/deep mycoses, cryptococcosis, urinary candidiasis

Answer 12

All off licenced and not often used as diseases are rare in UK
Amphotericin B- injectable
Fluconazole- oral/ Injectable
Flucytosine- oral/injectable

Question 13

Antifungals used for ringworm in rabbits and small mammals

Answer 13

ALL OFF LICENCE
Itraconazole- oral,systemic
Enilconazole- skin rinse
Miconazole- shampoo, ajunctive
Chlorhexidine- shampoo/foam/spray/otic solution/wipes; synergistic with miconazole, ineffective alone
Clotrimazole- cream

Question 14

Antifungal used for ringworm in horses

Answer 14

AlLL OFF LICENCE
Enilconazole- skin rinse
Miconazole- shampoo
Griseofulvin- systemic for ringworm; no longer vet product, human product available

Question 15

Antifungal for fungal keratitis (keratomycosis) in horses

Answer 15

Clotrimazole- cream, off licence

Question 16

Antifungal for ringworm in cattle

Answer 16

Anilconazole- on licence, skin rinse

Question 17

Antifungal for candidiasis aspergillosis in non-food-producing birds

Answer 17

Itraconazole- licenced
Voriconazole- licenced, EXPENSIVE
Nystatin- off licence
Amphotericin B- off licence

Question 18

Antifungl used for fungal derematitis (dermatomycosis) in repltiles

Answer 18

Itraconazole- off licence
F10 products