Antifungal drugs (3 Q's on the test)

Question 1

fungi differ from bacteria in that they are eukaryotes and so they have … ribosomes compared to bacterial … ribosomes. therefore many antibacterial agents are ineffective

Answer 1

80S

70S

Question 2

fungi are … growing and much … than bacteria

Answer 2

slow

larger

Question 3

fungi have a … cell wall instead of … cell walls in bacteria

Answer 3

rigid (chitin/glucans)

mucopeptide

Question 4

fungi contain … instead of cholesterol (mammalian) in cell membranes. basis of selective action or … and …

Answer 4

ergosterol

polyenes

azoles

Question 5

fungal infections occur in …. … tissues and they’re difficult to treat since antifungals are poorly soluble

Answer 5

poorly vascularized (skin, nails, hair)

Question 6

fungi cause a cellular … … leading to a … … which may interfere with drug penetration

Answer 6

immune response (antigens/polysaccharides)

granulomatous rxn

Question 7

in general,
short term, low toxicity therapy for …

long term thus higher toxicity for …

Answer 7

bacteria

fungi

Question 8

Griseofulvin MOA

Answer 8

microtubule inhibitor

Question 9

Griseofulvin: -static or

-cidal

Answer 9

-static but can be cidal at high doses

Question 10

griseofulvin is best taken with a … …

Answer 10

fatty meal (poor orally otherwise)

Question 11

T/F flucytosine is a prodrug

Answer 11

true

Question 12

Amphotericin B MOA

Answer 12

binding to ergosterol (makes pores)

Question 13

Ampho B: cidal or static?

Answer 13

cidal

Question 14

Ampho B is most important for …. infections

Answer 14

systemic

Question 15

Ampho B can increase the uptake of these two drugs:

Ampho B also have synergism with …

Answer 15

Rifampin

5-FC

Triazoles

Question 16

Ampho B has a wide spectrum which makes in #1 for serious systemic fungal infections BUT it has 4 drawbacks:

Answer 16

IV admin only

not soluble

protein bound

toxicities

Question 17

5-FC is absorbed well orally, soluble, well distributed, not metabolized and has good renal clearance but has the 3 following drawbacks

Answer 17

narrow spectrum
BMD
resistance

Question 18

Azoles- Imidazoles; Triazoles

static or cidal?

Answer 18

static but cidal at high dose

Question 19

Azoles MOA

Answer 19

binds/inhibits heme of lanosterol C14 alpha-demethylase (CYP51)