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43 Cards in this Set
- Front
- Back
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What types of infections are the 4th most common nosocomial infection?
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mycotic infections
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What 2 drugs are polyene antifungal agents?
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Amphotericin B
Nystatin |
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MOA: Amphotericin B and Nystatin
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bind to ergosterol in the fungal cell membrane causing pores to form (which leads to depolarization of the membrane and cell contents "leak out")
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What drug is the broadest spectrum of all antifungal agents?
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Amphotericin B*
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What's the advantage to using a liposomal formulation of Ampho B?
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shorter half-life --> less adverse effects
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what are two types of liposomal Ampho B drugs?
why do they have less side effects? |
1. Abelcet
2. Ambisome less S/Es due to reduced non-specific cholesterol binding |
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Why do you do a test dose when giving Ampho B?
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do a 1mg/hr test dose to monitor for hypotension and fever
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Do you do a dose alteration for Ampho B for pts that have renal failure?
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no dose alteration for pts in renal failure, however if the creatinine rises or doubles to >3 then either:
1. reduce dosing frequency 2. use lipid formulations |
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Why is Ampho B often called "amphoterrible"?
What are the signs of a bad rxn? What should you do to prevent this reaction? |
infusion-related reactions:
signs: rigors* premedicate w/ Tylenol, Benadryl, Hydrocortisone, or NSAIDS |
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What is a SLOW toxicity of Ampho B?
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nephrotoxicity
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What electrolyte problem is seen with Ampho B usage?
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severe Mg++ and K+ wasting
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How can Nystatin be given and how can it NOT be given?
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toxic if given systemically (IV)
topical usage |
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What are the clinical uses of 5-flucytosine?
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narrow spectrum:
Cryptococcus neoformans |
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MOA: 5-flucytosine?
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inhibits nucleic acid synthesis
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What happens if 5-Flucytosine is used alone?
What should it be used with? |
rapid emergence of resistance when used alone
synergistic with Ampho B/azoles |
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What are some important adverse effects of 5-flucytosine?
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1. GI: toxic megacolon, elevated transaminases/hepatomegaly
2. bone marrow: anemia, leukopenia, thrombocytopenia |
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What drugs has activity against candida?
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Nystatin commonly used for oral thrush, esophagitis, and vaginitis due to Candida
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What are the 4 important azoles to know and what type of azoles are they?
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Triazoles:
1. fluconazole 2. itraconazole 3. voriconazole 4. pozaconazole |
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What are all azoles active against?
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yeasts: Candida albicans, Cryptococcus neoformans
molds: Pseudoallescheria boydii |
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MOA: azoles
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MOA: azoles inhibit sterol biosynthesis by interference with CYP-450 dependent lanosterol C14 demethylation
this is a critical enzyme in ergosterol synthesis and it results in faulty cell membrane synthesis |
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Why are triazoles assoc with less toxicity than Ampho?
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Triazoles have greater affinity for fungal enzymes
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How is Clotrimazole used and for what?
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clotrimazole is used topically for superficial infections (i.e. Candida)
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What triazole has the greatest propensity to inhibit mammalian CYP-450 and what issues does this cause:
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Ketoconazole:
1. interferes with arenal/gonal steroid synthesis 2. increased number of drug interactions |
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What triazole requires gastric acid for absorption?
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Ketoconazole requires gastric acid for absorption
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What triazole is the TOC for dimorphic fungi?
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Itraconazole is "preferred" agent for Blastomyces, Histoplasma, Sporothrix
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What is it about the way that Itraconazole is made that makes it potentially harmful for people with renal impairment?
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propylene glycol dilutent in IV formulations is a risk for those with renal impairment
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What drug has drug interactions with H2 blockers, PPI inhibitors, Rifamycins, Astemizole, and terfenadine?
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Itraconazole
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What are the clinical uses for fluconazole?
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broad spectrum:
NOT for Aspergillus NOT for dimorphic fungi except nonmeningeal Coccidiodomycosis |
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For what is fluconazole the TOC?
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Fluconazole is the TOC for Cryptococcal Meningitis
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3 advantages to using fluconazole?
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1. high therapeutic window
2. few ADRs* 3. less hepatic CYP450 activity --> few drug interactions* |
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For what is Voriconazole the treatment of choice?
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Aspergillus
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What are some other uses for Voriconazole other than Aspergillus?
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1. increased use as prophylaxis and empiric therapy in neutropenia and bone marrow/stem cell transplant
2. selecting for Zygomycosis infections? |
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What triazole is most like Ampho B and why?
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Pozaconazole:
broad spectrum activity (less ADRs -- very well tolerated!) |
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What is pozaconazole active against?
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1. filamentous fungi
2. dimorphic fungi 3. Candida |
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What is Griseofulvin used for?
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only use is in systemic treatment of dermatophytosis of skin, hair, and nails
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What are Echinocandins?
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Echinocandins are broad spectrum antifungals:
1. fungicidal for yeasts 2. fungistatic for molds |
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What are the 3 Echinocandins?
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1. Caspofungin
2. Micafungin 3. Anidulafungin |
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MOA: Echinocandins?
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inhibit cell wall synthesis
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What are Echinocandins used with?
How are they NOT given? |
Echinocandins are synergistic with Ampho B
not given orally |
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Are adverse effects common with Echinocandins?
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Adverse effects are rare with Echinocandins
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Sprectrum of activity of Echinocandins?
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Candida (fungicidal)
Aspergillus (fungistatic) |
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What may severe inflammation indicate in a fungal case?
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may indicate a hypersensitivity reaction to the fungus and may be relieved with adjuvant topical steroids
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see cases at end of PPT
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see cases at end of PPT
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