Chapter 180 - antifungal therapy

Question 1

How does amphotericin B cause fungal cell death?

Answer 1

Binds to ergosterol in fungal cell membranes, increasing membrane permeability and leading to cell death

Question 2

Elimination half life of amphotericin b

Answer 2

Biphasic - 2-4 days then terminal half life of 15 days

Question 3

Organism from which amphotericin b is derived?

Answer 3

Streptomyces nodosus

Question 4

How to azole antifungals cause fungal cell death?

Answer 4

Inhibit fungal p-450 enzyme needed for development of ergosterol in fungal cell walls –> increased cell membrane permeability –> cell death

Question 5

Drugs that might interfere with the metabolism of azoles? Why?

Answer 5

Histamine-2 receptor antagonists, metabolised by p-450 enzyme system

Question 6

How does amphotericin b cause nephrotoxicity?

Answer 6

Binds to cholesterol in the proximal tubular cells, causing renal vasoconstriction and renal tubular acidosis