fungal infection Flashcards
3 main classifications of fungi
moulds: hyphae, aerobic
yeasts: sphere, anerobic
dimorphic fungi
_____ synthesized by the fungi cell membrane, providing structural support and permeability
Ergosterol
fungi has ___ (which structure)_____ resistant to bacterial cell wall inhibitor agents due to _______
Cell wall is composed of rigid, multilayered polysaccharides (resistant to bacterial cell wall inhibitor agents such as penicillins + cephalosporins due to lack of peptidoglycans)
candida
yeast
skin and mucous membrane
dermatophytes
mould
skin/hair/nail
dermatophytes require __ for growth
keratine
what are the three main groups of antifungal medicaiton
polyenes
alllylamines
azoles
MOA of polyenes
polyenes work by binding to ergosterol and fungal cell membranes, creating pores that cause cell leakage and death.
MOA of allylamines
Allylamines inhibit the enzyme squalene epoxidase, disrupting ergosterol synthesis, which is essential for fungal cell membrane integrity
MOA of azoles
Azoles also target ergosterol synthesis but inhibit a different enzyme, lanosterol 14A dimethylase, preventing the formation of ergosterol and leading to cell membrane instability.
nystatin is a
polyenes
how is polyenes excreted
unchanged in feces
nystatin _____ killing
Time-dependent killing
Preferred agent for infant oral candidiasis
nystatin
allylamines example
terbinafine
terbinafine is commonly used to treat
tinea infection
less effective for yeasr
adverse effect of terbinafine
hepatotoxicity,
monitor ___ for terbinafine
LFT
terbinafine has ___ killing
Concentration-dependent killing
special population oral terbinafine
not safe for infants and pregnant women
azoles are fungalcidal or fungalstatic
fungalstatic
adverse effects of azoles
hepatotoxicity, QT prolongation
monitor azoles
LFT’s, renal function
drug interactions of azoles
drugs metabolized via: CYP3A4 (i.e. PPI’s, carbamazepine) CYP2C9 (i.e. warfarin, NSAIDs)
