Antifungals

Question 1

Another name for fungal diseases?

Answer 1

Mycoses

Question 2

Types of Mycoses…

Answer 2

Superficial: affect scalp, nails, skin, mucous membranes, not life threatening.
Systemic: affect internal organs and fatal in immunocompromised.
Commensal: Candida Albans.
Environmental: Aspergillus fumigation / Cryptococcus neoformans.

Question 3

Anti fungal drug targets:

Answer 3

Fungal Cell Wall - skeletal/matrix components, complex structure, crucial for survival.
Skeletal Cell Wall - Glucan, B1-6 Glucan, B1-3 Glucan, Chitin.
Matrix Cell Wall - Manan

Question 4

Those at risk of developing fungal infection…

Answer 4

Impaired immune system: HIV, AIDS, transplant, premature, cancer, ICU.
Menstrual cycle in women.

Question 5

Mechanism of Echinocandins…

Answer 5

Inhibit enzyme B1-3 and block synthesis. Target plasma membrane, containing ergosterol to grow/survive.

Caspofungin / Micafungin.

Question 6

Mechanism of Polyene Antifungals…

Answer 6

Kill existing cells by binding to ergosterol in plasma membrane, form pores to disrupt membrane integrate > kidney failure.

Question 7

Examples of Polyene Antifungals…

Answer 7

Amphotericin B - ABLC/ L-ampB formulations.

Nystatin - oral/GI infections.

Question 8

Mechanism of Azoles…

Answer 8

Inhibit new cell production by inhibiting ergosterol biosynthetic enzymes and blocking biosynthesis causing toxic accumulation, causing growth arrest.

Question 9

Examples of Azoles…

Answer 9

Imidazoles/ Triazoles - fungistatic, inhibit LC14D, higher affinity for enzyme, more potent.
Allylamines - inhibit earlier stage (Terbinafine, Laminal, Amorolfine)

Question 10

RNA/DNA synthesis targeting Antifungals…

Answer 10

Toxic antimetabolite inhibiting RNA/DNA synthesis, high resistance, used with azoles.

Flucytosine.