What is the target of the azoles?
Lanoesterol to Ergosterol synthesis
What fungi is Griseofulvin used for?
What drugs are added along with Nystatin in Panalog?
What is the specific mechanism by which Terbinafine works?
Inhibits the synthesis of ergosterol
Does so by blocking the enzyme squalene monoxygenase therefore inhibiting the conversion of squalene to sterols
Accumulation of toxic intermediate squalene occurs
How are azoles distributed throughout the body?
Tissues with high lipid content
How is clortrimazole or Miconazole given?
Topically for treatment of yeast or dermatophyte infections
Nasal infustion for nasal aspergillosis
How is terbinafine used to treat birds?
Systemic mycotic infections
What adverse effects are seen with Amphotericin B?
What is posaconazole used for?
Otic + oral preperations
How is Amphotericin B eliminated?
65% excreted unchanged
How is Natamycin used in horses?
DOC for fungal keratitis
What are the two anti-fingal drugs that do not target the cell wall/membrane?
Why is the action of Griseofulvin so slow?
Infected cells are shed and replaced with uninfected cells
When is terbinafine fungistatic?
Which azole is best at reaching the cerbropinal fluid?
Fungus susceptible to Amphotericin B - (5)
What fungi does Azoles work against? (4)
What is the target of Griseofulvin?
What animals is Amphotericin B used in?
How does renal toxicity occur due to Amphotericin B?
Causes renal vasoconstriction
Damage to tubular epithelium
What are the adverse side effects of flucytosine?
Mild GI upset
Rarely - Bone marrow suppression
Where does griseofulvin distribute?
Precursor cells of skin, hair shafts, and nails
How is terbinafine adminstered?
Oral or Topically
What fungi does Terbinafine not reach the appropriate MIC?
How is Nystatin used in poultry?
Feed-additive to prevent crop mycosis + mycotic diarrhea
How are azoles absorbed?
With food that stimualtes bile flow
Why is fluconazole + itraconazole more likely to be choosen for systemic mycoses infections?
longer half lives
How is terbinafine used in dogs and cats?
How is terbinafine metabolized and excreted?
Metabolized in the liver (demethylated + deaminated + Dealkylated)
Excreted into the urine
Where does terbinafine distribute?
Skin and into sebum
How is ketoconazole given?
for 3 to 6 months when used for systemic infections
How are the azoles metabolized?
Microsomal enzymes (CYP450) of the liver
Excreted in the bile
How does terbinafine move through the body?
99% is attached to albulmin
Other anti-fungal agents that do not belong in specific groupings (3)
How can you increase the absorption of griseofulvin?
High fat foods
What are the three groups of anti-fungal drugs?
How is flucytosine given?
3 to 4 times a day
minimum of 4 weeks
How does terbinafine differ from azoles in regards to metabolism?
Does not block cytochrome P450 enzymes
What is the specific mechanism of action for Griseofulvin?
Binds to microtubules of certain fungi and destroys the mitotic spindle structure
How is fluconazole and itraconazole administered?
Oral or IV to dogs + Cats for systemic mycoses
Given for 1 to 3 months
What is the half life of Amphotericin B?
24 to 48 hours
1 to 2 weeks
***remember it is biphasic
When is terbinafine fungicidal?
What is the target of terbinafine?
Squalene to Squalene epoxide synthesis
What are the adverse effects of the azoles?
Vomiting, Diarrhea in cats
What is the target of Echinocandins?
What are the adverse effects of Nystatin + Natamycin?
What animals is giseofulvin used in?
What is the topical treatment of choice for canidia + aspergillus when it comes to the azoles?
Dermatophyte infections as well
What fungi do Nystatin + Natamycin work against?
How is Nystatin + Natamycin administered?
Topically to eye + ear + skin
Orally for mucosal infections of mouth + GI tract
What are the adverse effects of griseofulvin?
Leukopenia + anemia in kittnes
Teratogenic in pregnant cats
What is ketoconazole used for?
Dogs + Cats + Horses + Birds
Systemic mycoses + severe yeast infections
What situation is flucytosine used alone for treatment?
Aspergillosis + Candia infections in some birds
What is the exact mechanism of action for polyene agents?
Interaction with sterol of fungal membrane (Ergosterol) resulting in the loss of intracellular components
= Pore formation
Where is griseofulvin stored?
Growing keratin cell producing skin + hair + horn
How is griseofulvin adminstered?
orally BID in dogs and cats
orally SID for horses
How is griseofulvin aborbed?
25% to 70%
Where is flucytosine distributed?
Well distributed, includes the CNS
What is flucytosine FUNGICIDAL against?
How is Amphotericin B adminstered?
Diluted in 5% dextrose + given IV
How is Nystatin absorbed and excreted?
Not absorbed well
Excreted in feces
What is the specific mechanism of action for flucytosine?
Metabolic antagonism of fungal DNA + RNA
Converted to 5-fluorouracil which interferes with fungal DNA/RNA synthesis
How is flucytosine metabolized and excreted?
Excreted in urine
What is Amphotericin B mixed with to reduce toxicity?
What specific enzyme does flucytosine inhibit?
When is flucytosine combined with amphotericin B?
Treatment of cryptococcus in dogs + cats
What physiological condition in cats and dogs can be treated with Ketoconazole?
What is amphotericin B mixed with to get into CNS, bone, or ocular infections?
What is the specific mechanism of action when it comes to Azoles?
Inhibits synthesis of ergosterol
Leads to depletion of ergosterol in cell membrane + accumulation of toxic intermediates
Increases membrane permeability + inhibition of fungal growth