Antifungal drugs III

Question 1

Flucytosine: MOA

Answer 1

converted to 5-fluorouracil (via cytosine deaminase) -> interferes with DNA synth -> cell death
-high selective toxicity bc host cells lack deaminase

Question 2

Flucytosine: PK props

Answer 2

• oral
• good distribution to tissues (including CNS)
• renal (90% unchanged in urine)

Question 3

Flucytosine: adverse rxns

Answer 3

• toxic when given with Amphotericin B

- prolonged high levels -> BM dep, abnl liver function, hair loss

Question 4

Flucytosine: pharmacotherapy

Answer 4

-serious infections of cryptococcosis, candidiasis and chromoblastomycosis

Question 5

Griseofulvin: MOA

Answer 5

binds to MTs -> inhib fungal mitosis -> can’t process new cell wall components -> fungistatic

Question 6

Griseofulvin: PK props

Answer 6

• oral (take with fatty foods) –has affinity for diseased skin
• fecal excretion

Question 7

Griseofulvin: adverse rxns

Answer 7

-hypersensitivity rxns most common – skin rashes, urticarial, angioneurotic edema

Question 8

Griseofulvin: pharmacotherapy

Answer 8

• severe dermatophytosis (superficial) involving skin and hair or fingernails or toenails
• not frequently used

Question 9

Pentamidine: MOA

Answer 9

inhib protein and nucleic acid synthesis

Question 10

Pentamidine: PK props

Answer 10

IV/IM

-inhalation for P. jirovici PNE

Question 11

Pentamidine: adverse rxns

Answer 11

• severe toxities
• leukopenia, hypoglycemia, hypotension (IV use)
• nephro/hepatotoxicity

Question 12

Pentamidine: Pharmacotherapy

Answer 12

• wide variety of protozoa
• P. jirovici (carinii) PNE in AIDS pts
• Bactrim preferred for tx in non-AIDS pts and for prophylaxis in all pts