Antifungals Flashcards
What can fungus be divided into?
Yeast and mold
What are the types of yeast?
Candida, cryptococcus, pneumocycstis
What are the types of molds?
Dermatophytes, aspergillus, and rhizopus
What are the traits of yeast?
Ovoid or spherical, and single cells multiply by budding and division. (Histoplasma)
What are the traits of mold?
Filamentous fungi grow as a multinucleate branching, hyphae forming mycelium like ringworm
What are mycotic infections?
Cutaneous dermatophytosis or opportunistic infections caused by fungus on the skin.
What types of fungus can cause cutaneous dermatophytosis (ringworm)
The tineas
What types of fungus can cause opportunistic infections?
Candida aspergillus cryptococcosis Coccidioidomycosis and histoplasmosis
What is the most common type of fungus that causes skinfold infections or thrush?
Candida
What is Tinea incognito?
It is Tania that has a clinical appearance that has been altered by inappropriate treatment like a topical steroid cream, and it causes the original infection to slowly extend. These should be treated with an inappropriate antifungal medication and give the patient and antipruritic agent.
What are some preventative measures to prevent fungal infections?
Keep skin clean and dry do not share towels, clean showers with bleach, wash, socks, towels, and bath mats and very hot water. Avoid long periods of exclusive footwear and avoid bare feet in public pools and gym dressing rooms.
Which three classes of antifungal drugs, alter cell membrane permeability
Polyene macrolides, azole derivatives, and Allyamines
Which class of antifungals inhibit, DNA and protein synthesis?
Pyrimidine analog flucytosine
Which antifungal class of drugs acts by disrupting cell wall integrity
Echinocandins (IV only)
Which class of antifungal drugs is most useful for opportunistic infections?
Echinocandins
Which antifungal drug is used for amino compromised conditions of systemic candidiasis
Amphotericin B
Which class of antifungals acts by inhibiting ergosterol synthesis?
Azoles
What are the exceptions for fungal treatments that are systemic?
Nail mycoses, tinea capitis, infections that are resistant to topicals, and invasive fungal infections in immunocompromised patients.
What does the efficacy of topical antifungal depend upon?
Type of lesion mechanism of drug action, viscosity, hydrophobicity, and acidity of the formulation
What are the preferred formulas for topical antifungal?
Creams solutions and powders
How does antifungals that are systemic impact metabolism and excretion?
They impact G.I. function they impact polymorphisms of CYP2C19 genes and they impact drug interactions and some antifungals inhibit clearance of other drugs
What is the antifungal Polyene macrolide that potentially binds to fungal ergosterol which alters cellular permeability?
Amphotericin B
What are the adverse effects of systemic antifungals?
Hepatotoxicity, G.I. upset, hepatitis, cholestasis, and hepatic failure.
What drugs do ketoconazole interact with?
CYP 450 inhibitor interacts with benzodiazepines bupropion carbamazepine corticosteroids Protease inhibitors sulfonylureas and warfarin.
What does fluconazole increase the action of?
Benzodiazepines buspirone corticosteroids losartan sulfonylureas warfarin, statins and clarithromycin
What drugs does griseofulvin decrease the action of?
Anticoagulant, oral contraceptives, hormone replacement, drugs, cyclosporine, and alcohol.
Which antifungal can APN not prescribe?
Capsofungin
What is the first line treatment for finger and toenail onychomycosis?
Turbinafine
What is the first line of treatment for candidia that is esophageal oral or vaginitis
Fluconazole
What is the first line of treatment in tinea capitis for pediatric patients and tinea pedis
Griseofulvin
What happens when a fungal infection is treated with a topical steroid
Tinea incognito occurs and it makes it much more difficult for the provider to identify the I
Etiology of the lesion
What is the first line of treatment aspergillosis and candidemia
caspofungin
What drug class and root of administration would you consider for the treatment of toenail fungal infection
A systemic allylamine should be considered first line
All oral and systemic antifungal drugs have what common adverse effect
Hepatotoxicity
Which class of antifungals when given systemically shows the lowest rate of drug interactions
The Echinocandins
What is the difference untreated tinea and incognito tinea
Incognito has a less raised margin, is less scaly, and more pustular, more extensive, and more irritated
What are the three important things to consider when prescribing antifungals
Spectrum of activity, metabolism, and excretion.
What drug would you give for thrush?
Nystatin
What drug would you give for tinea capitis, pedis, and corporis
Terbinafine
What drug do you give for most candida infections?
Fluconazole
When do you give fluconazole for tinea?
When it’s pedis
What is the first line of treatment for thrush?
Nystatin
