Antifungal

Question 1

Amphotercin B

Answer 1

Subclass:
Polyenes

Closely related drugs:
Nystatin

Mechanism:
Binds ergosterol&raquo_space;> cholesterol, decreasing fluidity
creates pore leaking for K

Adverse effects:
Acute toxicity (fever, chills, nausea, vomiting, and hypotenesion)
nephrotoxicity

Notes:
Used serious systemic infections

Question 2

Flucytosine

Answer 2

Mech:
forms fluorouracil in cells and inhibits thymidylate synthase and DNA synthesis

Adverse effects:
Reversible bone marrow depression
Alopecia

Notes:
Penetrates CSF
Used with Amp B to lower resistance from fungi to drugs

Question 3

Terbafine

Answer 3

Mech:

Inhibits squalene epoxidase (pathway to lanosterol and ergosterol)

Question 4

Caspofungin

Answer 4

Subclass:
Echinocandins

Closely related drugs:
Micafungin/anidulafungin

Mech:
Inhibits synthesis of Beta (1-3) glucan required for cell wall

Question 5

Fluonzaole

Answer 5

Subclass:
Azoles

Closely related drugs
Posa-/keto-/itra-conazole
clotrimazole/miconazole = topical

Mech:
inhibits ergosterol biosynthesis by inhibiting P450

Notes:
Penetrates CSF, used for yeast but not aspergillus
CYP inhibitor (increases drug/drug interaction)

Question 6

Voriconazole

Answer 6

Subclass:
Azoles

Mech:
Inhibits ergosterol biosynthesis by inhibiting P450

Adverse effects:
Transient visual distrubances

Notes:
used for yeast and aspergillus
CYP inhibitor (increases drug/drug interaction)