Chapter 24: ID III - Antifungals & Antivirals Flashcards
What are the 3 types of fungal classification
Yeasts
molds
dimorphic
Invasive disease with Zygomycetes (Mucor species and Rhizopus species) is commonly referred to as
Mucormycosis
Which fungi are yeasts
The candida species:
- C. albicans
- C. tropicalis
- C. parapsilosis
- C. glabrata
- C. krusei
- Crypotococcus neoformans
Which fungi are molds
Aspergillus species
Zygomycetes (Mucor and Rhizopus species)
Which fungi are dimorphic
Histoplasma capsulatum
Blastomyces dermatitidis
Coccidioides immitis
What is the conventional form of Amphotericin B
Amphotericin B deoxycholate (many toxicities)
The lipid formulations of Amphotericin B are used clinically because
they have fewer toxicities (decreased infusion reactions, decreased nephrotoxicity)
Amphotericin B is active against
Yeasts: Cryptococcus neoformans
Mold: Aspergillus spp
Dimorphic fungi
Amphotericin B deoxycholate and liposomal Amphotericin B formulation
Injection
Conventional Amphotericin B for injection doses should not exceed ___ mg/kg/day d/t risk of ____
1.5 mg/kg/day
Cardiopulmonary arrest
Amphotericin B SE
Infusion-related: fever, chills, HA, malaise, rigors
Other: ↓ K & Mg, nephrotoxicity
Amphotericin B must be diluted in ___ only, & lipid formulations must be ___ during preparation
D5W
filtered
Amphotericin B deoxycholate (conventional formulation) requires ___ to reduce infusion-related reactions
Premedication with APAP or NSAID + Benadryl and/or hydrocortisone
Liposomal Amphotericin B brand name
AmBisome
Flucytosine penetrates fungal cells and is converted to
Fluorouracil
Flucytosine should not be
Used alone due to development of resistance
Flucytosine is recommended for use in combination with ____ for treatment of
Amphotericin B Invasive Cryptococcal (meningitis)
Flucytosine side effects
Myelosuppression
MOA of azole antifungals
Decreases ergosterol synthesis and cell membrane formation
Azoles are ___ of the CYP450 system
inhibitors
Fluconazole has limited efficacy against _____ due to resistance and ____ is considered fluconazole-resistant
C. glabrata
C. krusei
Fluconazole can be used for yeast infections and ____ infections
nail bed (onychomycosis)
Primary use of itraconazole
nail bed infections (onychomycosis)
What is the treatment of choice for Aspergillus
Voriconazole
Remember: V looks like upside down A
All azole antifungals can cause
Increased LFTs
Risk for QT prolongation
Many drug interactions
What is the only azole that requires renal dose adjustment
Fluconazole
Hepatotoxicity with this azole has led to liver transplantation
Ketoconazole
Which azole can cause HF
Itraconazole
Which azole can cause visual changes and phototoxicity
Voriconazole
Remember: Visual & Vori
Which azole should be taken with food
Posaconazole
itraconazole
tablets and capsule
What is the IV:PO ratio for all azoles
1:1
Which azoles have SBECD vehicle
voriconazole
and
posaconazole
What formulations does fluconazole come in
IV and PO
Fluconazole dose for vaginal candidiasis
150 mg PO x1
Ketoconazole oral tabs should only be used when
Other effective antifungal therapy is unavailable or not tolerated
Which 2 azoles penetrate the CNS adequately to treat fungal meningitis
Fluconazole
voriconazole
Voriconazole brand name
Vfend
Vfend IV
What should be done if a patient is going to be treated with voriconazole and CrCl < 50 mL/min
The IV vehicle accumulates, so treat with oral voriconazole
Voriconazole SE
Visual changes
↑ LFTs
↑ SCr
CNS toxicity (hallucinations)
T/F: Vfend should be taken on an empty stomach
True
Posaconazole brand name
Noxafil
T/F: Posaconazole should not be taken with food
False- take with food daily
Which azole causes QT shortening instead of prolongation
Isavuconazonium sulfate
Which azole requires a filter
Isavuconazonium sulfate
Azoles can increase the effects of which drug
Warfarin (monitor INR)
Absorption of which two azoles is pH-dependent
Itraconazole and Ketoconazole (↑ pH will ↓ absorption)
If PPIs or H2RAs must be used while on ketoconazole, what should be done
An acidic beverage (such as non-diet cola) to provide an acidic environment for absorption
Echinocandins MOA
Inhibit synthesis of beta (1,3) D-glucan,
an essential component of the fungal cell wall
Echinocandins are effective against most ____ species
Candida
the word candin is in the name
Activity of Echinocandins includes
Aspergillus spp
Echinocandins formulation
Injection only
Caspofungin brand name
Cancidas
Micafungin brand name
Mycamine
Which drugs are Echinocandins
Caspofungin
Micafungin
Echinocandins warning
Histamine-mediated symptoms
All Echinocandins are given how many times a day
Once daily
T/F: Echinocandins do not require renal dose adjustment
True
Nystatin formulations
Suspension
tablet
How should nystatin suspension be used for oral candidiasis
Swish in the mouth and retain for as long as possible (several minutes) before swallowing
Terbinafine brand name
Lamisil AT
Griseofulvin is indicated for fungal infections of
hair, skin and nails
Terbinafine comes in which formulations
Topical (Rx and OTC)
Clotrimazole comes in a 10 mg ___
troche/lozenge
Clotrimazole topical and vaginal forms brand name
Mycelex
Griseofulvin CI
pregnancy
Griseofulvin SE
Photosensitivity,
↑ LFTs
Griseofulvin should be taken with
a fatty meal to increase absorption or with food/milk to avoid GI upset
Terbinafine warning
Hepatotoxicity
Terbinafine SE
HA, ↑ LFTs
Griseofulvin can ↑ metabolism of
hormonal contraceptives which can lead to contraceptive failure
Preferred antifungal regimen for mild disease of Candida albicans (thrush)
Topical antifungals (clotrimazole, miconazole)
Preferred antifungal regimen for moderate-severe disease or HIV+ of Candida albicans (thrush)
Fluconazole
Preferred antifungal regimen for Candida albicans (esophageal infection) & the alternative
Fluconazole
Alt: Echinocandin
Preferred antifungal regimen for Candida krusei & glabrata (bloodstream infection) & the alternative
Echinocandin
Alt: Amphotericin B
Preferred antifungal regimen for invasive Aspergillus spp & the alternative
Voriconazole
Alt: Amphotericin B, isavuconazonium
Preferred antifungal treatment for Cryptococcus neoformans (Meningitis)
Amphotericin B + flucytosine (5-FC)
Preferred antifungal treatment for dermatophytes (nail bed infection) & the alternative
Terbinafine or itraconazole
Alt: Fluconazole
Which antivirals are used for influenza
Neuramidase inhibitors: oseltamivir, zanamivir
Endonuclease inhibitor: Baloxavir
Neuramidase inhibitors MOA
reduces the amount of virus in the body by inhibiting the enzyme which enables release of new viral particles from infected cells
Neuramidase inhibitors decrease the duration of influenza symptoms by about how many days, while also reducing complications from influenza
1 day
Neuramidase inhibitor should be started within how many hours of illness onset
48 hrs
What is an advantage of the Endonuclease inhibitor, Baloxavir
It is a single dose regimen
Baloxavir should be started within how many hours of symptom onset
48 hours
Oseltamivir comes in which formulations
Capsules and suspension
Oseltamivir dosing for age > 12 years
75 mg BID x 5 days
Oseltamivir ppx dosing for age > 12 years
75 mg daily x 10 days
Oseltamivir warning
Neuropsychiatric events
Zanamivir comes in which formulation
Inhalation
Zanamivir warning
Bronchospasm
do not use in asthma/COPD or with any breathing problems
HSV-1 is most commonly associated with ___ disease
oropharyngeal
HSV-2 is most commonly associated with ___ disease
Genital
Acyclovir brand name
Zovirax
Valacyclovir brand name
Valtrex
Valacyclovir is a prodrug of
acyclovir
What drug is used for cold sores (herpes simplex labialis)
Zovirax cream
Famciclovir is a prodrug of
penciclovir
Antivirals for herpes simplex virus and varicella zoster virus warnings
Caution in patients with renal impairment, the elderly and those receiving nephrotoxic agents
Acyclovir dose is based on which weight
IBW, even in obese pts
When is the best time to use medication for cold sores
during prodromal symptoms (tingling, itching, soreness)
Docosanol brand name
Abreva
Which drugs are used for cold sore
Docosanol & acyclovir
Dosing for Docosanol for Cold sores
Apply 5x daily at first sign of outbreak
Dosing for acyclovir for cold sores
Apply 5x per day for 4 days
Treatment for genital herpes must be initiated during the prodrome or within how many days of lesion onset
1 day
What is the least expensive med to treat genital herpes
Acyclovir (but must be dosed up to 5 x per day)
Which medications can be used to treat genital herpes
Acyclovir
Valacyclovir (good for pts with adherence issues)
Famciclovir
What is the most commonly identified cause of viral encephalitis
HSV
How is HSV encephalitis treated
IV acyclovir
Shingles rash symptoms
itchy, tingly, very painful, unilateral rash
Cluster of fluid-filled blisters, often in a band
Antiviral therapy for shingles is most effective when started within __ hours of the onset of rash
72 hours
How can shingles pain be treated
- topical medications (lidoderm patch)
- Neuropathic pain: pregabalin, gabapentin, duloxetine, and TCAs
- NSAIDs or opioids
What is chronic pain after recovery from shingles called
postherpetic neuralgia
How long should antiviral therapy be used for in Shingles treatment
7 days
Cytomegalovirus occurs in which pt populations
severely immunicompromised states
(e.g., AIDS, transplant recipients)
Cytomegalovirus commonly causes what symptoms
Retinitis, colitis, esophagitis
What are the treatments of choice for CMV
Ganciclovir
and
valganciclovir
Which drugs should be used for refractory cases of CMV
Foscarnet and cidofovir
ganciclovir brand name
Cytovene
Valganciclovir brand name
Valcyte
What is the prodrug of ganciclovir
Valganciclovir
Which drug can be used for CMV retinitis
Foscarnet
Ganciclovir must be prepared in which kind of water
sterile, NOT bacteriostatic
Ganciclovir & valganciclovir BW
Myelosuppression
Ganciclovir & valganciclovir suspension must be
refrigerated
Foscarnet BW
Renal impairment
What is another name for infectious EBV
mononucleosis or “mono”
How is EBV spread/transmitted
Bodily fluids, primarily saliva, and can spread by kissing