Flashcards in Antifungals Deck (21):
what are the three major categories of pathogenic fungus
yeast, molds, other (endemic mycoses, pneumocystis jiroveci)
what can you target on the fungal structure?
cell walls made of ergosterol. Beta 1,3 glucan synthase, an enzyme that makes cell walls
list the 4 triazole antifungals
fluconazole, itraconazole, posaconazole, voriconazole
triazole mechanism of action
impede ergosterol synthesis through direct inhibition of P450 dependent enzyme 14-alpha-sterol-demthylase. stops fungal growth
what is the most potent triazole
triazole adverse effects
pretty safe. liver enzyme abnormalities, monitor if long term treatment. GI side effects. Voriconazole causes visual disturbances
triazole drug interactions
all triazoles are substrates and potential inhibitors of CYP450. important to assess for drug interactions! fluconazole has lowest drug interaction potency
what does fluconazole treat
susceptible candidiasis. severe thrush/candidiasis.
what does itraconazole treat
secondary treatment and prophylaxis of systemic histoplasmosis
what does voriconazole treat
what does posaconazole treat
prophylaxis of aspergillosis/candidiasis in immunocompromised people
amphotericin B mechanism of action
travels across cell wall and inserts into the cell wall. pulls it apart to create pores
adverse effects with amphotericin B
nephrotoxicity! watch serum creatinine. Acute infusion related reactions such as chills, fever, rigors. Electrolyte abnormalities. many patients unable to tolerate full course of conventional amphotericin B
how do we make amphotericin B have less side effects?
lipid formulations. more renal protective. less infusion related side effects. putting it in lysosomes gets it taken up by the fungus, not the rest of the body!
caspofungin, micafungin, anidulafungin
what are the echinocandins used for?
candida infections, refractory aspergillus, esophageal candidiasis, empiric antifungal for febrile neutropenic patients
echinocandin mechanism of action
inhibits beta 1,3 glucan synthase. prevents making of the cell wall and destroys the cell. works well on yeast, less so on molds
what do echinocandins have great activity against?
excellent against candida!
flucytosine mechanism of action
pyrimidine analogue that inhibits DNA and RNA synthesis. only oral formulation
flucytosine spectrum of activity
active against cryptococcus and some candida species. clinically only used in combos!