Infectious Diseases III: Antifungals & Antivirals

Question 1

Amphotericin B MOA

Answer 1

binds to ergosterol, altering cell membrane permeability and causing cell death

Question 2

Amphotericin B formulations

Answer 2

Amphotericin B deoxycholate = conventional, many toxicities
Amphotericin B lipid formulation = fewer toxicities compared to conventional

Question 3

Amphotericin B Boxed warning

Answer 3

mixing between conventional and lipid formulation, conventional should not be more than 1.5mg/kg/day can cause cardiopulmonary arrest and death

Question 4

Ampthotericin B Side effects

Answer 4

infusion related, fevers, chills, headache, dec K/Mg, nephrotoxicity

** conventional req premed to reduce incidence **

Question 5

Amphotericin B DI

Answer 5

additive risk with other nephrotoxic agents
can inc risk of digoxin toxicity, use caution with any other agent that dec K/Mg

Question 6

Flucytosine MOA

Answer 6

goes inside cells, converts to fluorouracil and interferes with fungal RNA and protein synthesis

using in combo with Amp B due to resistance

Question 7

Flucytosine and AmpB combo used in….

Answer 7

invasive cryptococcal (meningitis) or candida infections

Question 8

Azole MOA

Answer 8

decrease ergosterol synthesis and cell membrane formation

Question 9

Fluconazole info

Answer 9

only azole that req renal dose adjustment, rest cleared hepatically

works against C.albicans, parapsilosis and tropicalis
Limited activity against C. glabrata and C kruse = resistant

Question 10

primary use for itraconazole?

Answer 10

dimorphic fungi (blastomycoses & histoplasma)
nail bed infections

Question 11

Voriconazole is treatment of choice for….

Answer 11

aspergillus

Question 12

which azole can treat fungal meningitis?

Answer 12

fluconazole and voriconazole, both penetrate the CNS

Question 13

Itraconazole boxed warning

Answer 13

can worsen or cause HF, dont used to treat onychomycosis in pts with ventricular dysfunction or hx of HF

Question 14

Ketoconazole warnings

Answer 14

hepatotoxicity which has led to liver transplantation or death
QT prolongation

use only as last resort

Question 15

Voriconazole warnings and SE

Answer 15

SE: visual changes, inc LFTs, Scr, CNS tox
Warnings: hepatotoxicity, visual disturbances, phototox, QT prolong

avoid direct sunlight, caution driving at night

** take on empty stomach **

Question 16

Isavuconazonium info

Answer 16

causes QT shortening not prolongation

micron filter req when admin IV

Question 17

Azole drug interactions

Answer 17

Itraconazole/ketoconazole req acidic environment, so if on PPI drink soda before taking

PPI can dec absorption of posaconazole suspension, dont take w/ it

Question 18

Echinocandins (-fungins) MOA

Answer 18

inhibit synthesis of beta (1,3) D-glucan, part of fungal cell wall

active against candida species, used in combo against Aspergillus

Question 19

Echinocandins info

Answer 19

all given once daily
no dose adjustments in renal impairment

Micafungin req light protection during admin

Question 20

Griseofulvin info

Answer 20

used for fungal infection of skin, hair,nails

dont use in pregnant people, severe liver disease
take w/ fatty meal to inc absorb and dec GI upset
inc metabolism of hormone BC, use backup

SE: photosensitivity, inc LFTs

Question 21

Terbinafine Info

Answer 21

Lamictal = topical

Warning: hepatotoxicity
SE: headache, inc LFTs

Question 22

empiric treatment for Candida albicans thrush

Answer 22

mild = topical anti fungal
mod-severe = fluconazole

alternative = Nystatin

Question 23

empiric treatment for Candida albicans esophageal infection

Answer 23

fluconazole

alternative: echinocandin

Question 24

empiric treatment for Candida kruse and globarata, all candida blood stream infections

Answer 24

echinocandin

alternative: amp B, high dose fluc

Question 25

empiric treatment for aspergillus

Answer 25

Vorivonazole alternative: amp B, isavuconazonium

Question 26

Cryptococcus neoformans meningitis empiric treatment

Answer 26

ampB + flucytosine alternative: high dose fluc + flucytosine

Question 27

Dermatophytes empiric treatment

Answer 27

terbinafine or itraconazole Alternative: fluconazole

Question 28

Neuraminidase inhibitors

Answer 28

oseltamivir - tamiflu zanamivir peramivir

Question 29

to be most effective, neuraminidase inhibitors should be taken within....

Answer 29

48hrs of illness onset

Question 30

Baloxavir (Xofluza)

Answer 30

endonuclease inhibitor = MOA single dose still start within 48hrs of symptom onset

Question 31

Tamiflu treatment dosing

Answer 31

75mg BID X 5 days ( > 12 yrs old)

Question 32

Tamiflu ppx dosing

Answer 32

75mg QD X 10 days ( > 12 yrs old)

Question 33

Tamiflu warnings and SE

Answer 33

Warning: neuropsych events SE: HA, N,V preferred in pregnancy over others

Question 34

Zanamivir treatment dosing

Answer 34

Two 5mg inhalations BID X 5 days ( > 7yrs)

Question 35

Zanamivir ppx dosing

Answer 35

Two 5mg inhalations QD X 10 days (> 5 yrs) if household, X 28 days if community

Question 36

Zanamivir warnings

Answer 36

dont use in Asthma/COPD due to bronchospasm

Question 37

Peramivir dosing

Answer 37

600mg IV single dose for txm, < 50 CrCl renal adjust

Question 38

Acyclovir warning

Answer 38

use caution with renal impairment, elderly and the on other nephrotoxic drugs. hydrate well and infuse over 1 hr at least

Question 39

Initial oral herpes txm

Answer 39

Acyclovir - 200mg X 5 times daily or 400mg TID Valacyclovir - 1g BID

Question 40

Chronic suppression oral herpes txm

Answer 40

Acyclovir - 400mg BID Valacyclovir - 500mg or 1g QD

Question 41

HSV encephalitis txm

Answer 41

IV acyclovir 10mg/kg Q8H for 14-21 days

Question 42

Shingles Vaccine recommendations

Answer 42

> 50 yrs old or > 19yrs old if immunosuppressed

Question 43

Shingles txm

Answer 43

Acyclovir - 800mg 5 times a day for 7/10 days Valacyclovir - 1g TID for 7 days

Question 44

CMV txm of choice and what's back up?

Answer 44

Ganciclovir and valganciclovir Foscarnet and cidofovir back up Maribavir if resistant to everything else

Question 45

CMV ppx

Answer 45

Letermovir = getting stem cell transplant Ganciclovir/valganciclovir = sold organ transplant

Question 46

Ganciclovir/valganciclovir boxed warning

Answer 46

Myelosuppression

Question 47

Ganciclovir/Valganciclovir notes

Answer 47

females use contraception during txm and 30 days after males use contraception 90 days after

Question 48

Foscarnet boxed warnings

Answer 48

renal impairment, pre-hydration is important