Fungal

Question 1

Examples of azoles?

Answer 1

Fluconazole
Itraconazole
Voriconazole
Posiconazole

Question 2

Mechanisim of action of azoles?

Answer 2

inhibit ergosterol synthesis via inhibiton of CYP 450 enzyme

Ergosterol is a vital part of the cell membrane

Question 3

Indications for fluconazole?

Answer 3

Candida Albicans infection

- not good for non-albicans candida

Question 4

Indications for Itraconazole?

Answer 4

Aspergillous, Candida

Question 5

Indications for Voriconazole?

Answer 5

All candida species and aspergillous

Question 6

Indications for Posiconazole

Answer 6

Candida (all species)
Aspergillous
Zygomycosis (mucor etc.)

Question 7

Cautions in use of azoles?

Answer 7

CYP3a4 inhibitors
P-glycoprotein inhibitors
Lots of drug interactions
Caution in renal impairment

Question 8

Example of a polyene anti-fungal?

Answer 8

Amphotericin B

Question 9

Mechanism of action of amphotericin B

Answer 9

Binds to sterols in cell membrane and increases membrane permeability and pore formation

Question 10

Indications for amphotericin B

Answer 10

Aspergillous
Cryptococcus (first line for cryptococcal meningitis)
Mucor/Fusarium
Candida - particularly C. Glabrata and C. Krusei

Question 11

Side effects of amphotericin B

Answer 11

Renal impairment
Distal type 1 RTA
Electrolyte wasting
Infusion reaction

*Note - liposomal preparation decreases drug toxicity

Question 12

Mechanism of echinocandins?

Answer 12

inhibits synthesis of glucan in cell wall thereby inhibiting cell wall synthesis

Question 13

Example of echinocandin?

Answer 13

Caspofungan

Question 14

Indications for echinocandins?

Answer 14

Candida

Aspergillous

Question 15

Mechanism of action of Flucytosine?

Answer 15

inhibitor of fungal DNA synthesis

Question 16

Indications for flucytosine?

Answer 16

Cryptococcus

Candida

Question 17

What are some side effects of flucytosine?

Answer 17

Bone marrow suppression

Raised LFTs

Question 18

Treatment of crytpococcal meningitis?

Answer 18

Amphotericin B and flucytosine for 6 weeks - crosses BBB

Followed by fluconazole maintaince

Question 19

Risk factors for systemic candidiasis?

Answer 19

loss of gut integrity (particularly upper abdomen)
prolonged neutropenia (chemotherapy/immunosuppression)
central lines, TPN
Haemodialysis
ICU patient

Question 20

Clinical manifestations of disseminated candida?

Answer 20

sepsis
eye lesions - white exudates on retina
skin lesions - papules or pustules with an erythematous base
abscesses in liver, spleen, kidney, lungs, brain

Question 21

Treatment of disseminated candida?

Answer 21

Fluconazole if not C.glabrata or krusei and not severely unwell
Otherwise Voriconazole, Caspofungin, amphotericin B

Question 22

What is galactomannan assay?

Answer 22

a component of the cell wall of aspergillous that can be measured in serum

Question 23

What is the first line treatment for disseminated aspergillous?

Answer 23

Voriconazole

Question 24

What is the treatment for aspergillioma?

Answer 24

surgical removal

Question 25

Risk factors for mucor infection?

Answer 25

haematologic malignancy
poorly controlled diabetes
severe burns
iron chelating therapy (desferrioxamine)

Question 26

Complications of cryptococcus meningitis?

Answer 26

hydrocephalus

cryptococcoma