farm 2-6
Terms
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- what antifungals are cell membrane inhibitors?
-
amphotericin B
nystatin
fluconazole (azoles)
allylamine drugs (terbinafine)
ciclopirox - what antifungals inhibit RNA?
- flucytosine
- what antifungals inhibit mitosis?
- griseofulvin
-
polyene antibiotic -
Amphotericin B -
Amphotericin B
Class: polyene antibiotic
MOA: bind to ergosterol and form a pore (increase cell membrane permeability)
Use: severe systemic, subQ mycoses.. cryptococcal meningitis, histo, blasto, coccidio
AE: renal toxicity 90% {decreased GFR -> azotemia, hypokal, hypomg... chills, fever, headache (shake and bake)... liver, heart, hematopoietic toxicity (suppress EPO, anemia)... anaphylaxis, convulsions.. decrease dosage when electrolytes get bad
Contra: pregnancy, crosses placenta
Interaction: nephrotoxicity exacerbated by aminoglycoside, cyclosporine, pentamidine... hypokal careful in digitalis pt... increase anemia in zidovudine pt
Admin: IV - lipid formulations sequestered and slowly released from reticuloendothelial system - has decreased renal drug [] / toxicity -
Azole Derivatives-
Clotrimazole -
Clotrimazole
Class: azole derivative
MOA: inhibit 14-alpha-demethylase (cyto P450 enzyme) that converts lanosterol to ergosterol
Use: superficial mycoses - cadidiasis, tinea
MALASSEZIA FURFUR - HYPO/HYPERPIGMENTED LESIONS
AE: contact dermatitis, vulvar irritation, edema... typical azole effect: well tolerated, rash, liver, hematologic, GI
Contra:
Interaction: inhibit P450 enzymes - increase levels of warfarin, lovastatin, benzodiazepines, carbamazepine LIKE ERYTHRO & CLARITHRO MACROLIDES... rifampin decreases azole duration of axn
Admin: topical -
Azole Derivatives
Fluconazole -
Fluconazole
Class: azole
MOA: inhibit 14 alpha demethylase, enzyme that converts lanosterol to ergosterol
Use: fungal (cryptococcal) meningitis prophy and rx - penetrates CNS... candidasis (single oral dose for vaginal infection)
DOC crypto, candida, coccidio
AE: N/V/rashes/hepatitis
Contra: preg
Interaction: inhibit P450 enzymes
Admin: oral, IV (penetrates CNS).. good absorption, bad metabolism -
Azole Derivative
Itraconazole -
Itraconazole
Class: azole
MOA: inhibit 14 alpha demethylase, P450 enzyme that converts lanosterol to ergosterol
Use: blasto, histo (+AIDS histo), coccidio
onychomycosis, sporotrichosis (give K Iodide for cutaneous lesions)
AE: N/V/rash, hypokal, HTN, edema, headache
Contra: preg
Interaction: oral anticoag, statin, quinidine... inducers of P450 increase intraconazole metab
Admin: oral - need gastric acid for dissolution.. active metabolite -
Azole Derivative
Ketoconazole -
Ketoconazole
Class: azole
MOA: inhibit 14 alpha demethylase, a P450 enzyme that converts lanosterol to ergosterol
Use: NOT aspergillosus, shampoo for seborrheic dermatitis...
AE: inhibit human gonadal (testosterone) synth... inhibit adrenal steroid (cortisol synth)... N/V/anorexia, allergies, transient elevated serum transaminases
Contra: preg
Interaction: require gastric acid for breakdown and absorbed in gastric mucosa.. PPI, H2 inhibitor, sucralfate, antacids impair absorption... acidifying agents improve absorption in pt with achlorhydria
Admin: oral -
Azole Derivative
Voriconazole -
Voriconazole
Class: azole
MOA: inhibit 14 alpha demethylase, P450 enzyme that converts lanosterol to ergosterol
Use: invasive aspergillosis, DRUG RESISTANT CANDIDA, DRUGS RESISTANT TO FLUCONAZOLE, additive effects with caspofungin
AE: normal azole (N/V/rash, hematologic) + transient visual disturbance after dose
Contra: preg
Interaction: inhibit P450
Admin: oral, penetrates tissues/CNS well -
Echinocandin
Caspofungin -
Caspofungin
Class: echinocandin
MOA: inhibit cell wall glucan synthesis
Use: aspergillus, resistant candida, alternative use for allergic amphotericin B/ itraconazole
AE: fever, rash, nausea, phlebitis, flushing
Contra: it pt taking cyclosporine
Interaction: slowly metab by hydrolysis/ acetylation
Admin: -
Allylamine drugs -
Terbinafine -
Terbinafine
Class: allylamine
MOA: inhibit squaline epoxidase, enzyme for ergosterol synthesis
Use: superficial infections, onychomycosis, dermatophytoses, candida
AE: GI, headache, rash, taste/visual disturbance
Contra: nursing mom
Interaction: rifampin decreases serum terbinafine level... Cimetidine increases serum terbinafine level
Admin: topical, oral - Flucytosine
-
Flucytosine
Class:
MOA: inhibits thymidilate synthase (RNA synth)
Use: crypto meningitis, systemic candidiasis (used with amphotericin B)... systemic/ subQ mycoses
AE: reversible neutropenia, thrombocytopenia, bone marrow depression, reversible hepatic dysfxn, N/V/D, enterocolitis
Contra:
Interaction: dose must be adjusted in renal compromise pt
Admin: oral, penetrates CSF - Griseofulvin
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Griseofulvin
Class:
MOA: inhibits microtubule fxn, mitosis - concentrates in keratin precursor cells of dermis (works from inside out)
Use: superficial mycoses
AE:
Contra: alcohol - potentiates alcohol effects
Interaction: induces P450
Admin: oral - bioavailability increased by micronized drug particle + fatty meals - what are drugs used for systemic and subQ mycoses
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amphotericin B
itraconazole, fluconazole
voriconazole, caspofungin (drug resistant and invasive candidiasis and aspergillosus)
flucytosine - what drugs are used for superficial mycoses
-
clotrimazole
terbinafine
friseofulvin
nystatin - (binds ergocholesterol), for oral candida "swish and swallow"
ciclopirox (membrane structure), nail lacquer formation for onychomycosis
tolnaftate