Shared Flashcard Set

Details

Antifungals
Boards Review
10
Microbiology
Professional
10/18/2009

Additional Microbiology Flashcards

 


 

Cards

Term
Amphotericin B
Definition

1. binds ergosterol leading to pore formation and leakage of cellular contents (electrolytes)

2. Clinical use- systemic mycoses: cryptococcus, blastomyces, coccidioides, aspergillus, histoplasma, candida, mucor

3. Not absorbed orally- intrathecally for fungal meningitis (does not cross BBB)

4. Toxicity- fever/chills, hypotension, nephrotoxicity (reduced with hydration), arrythmias, anemia, IV phlebitis

5. Liposomal amphotericin reduces toxicity

6. Analgesics to alleviate infusion-related probs

7. Primary resistance unusual- fusarium, scedosporium, lusitaniae, guilliermondi

Term
Nystatin
Definition

1. Polyene antifungal with anti-candida activity

2. Binds ergosterol disrupting funal membranes- toxic for systemic use

2. oral solution swished and swallowed for oral candidiasis, topical for diaper rash or vaginal candidiasis

Term
Azole Antifungals
Definition

1.Fluconazole, ketoconazole, clotrimazole, miconazole, itraconazole, voriconazole

2. Inhibit fungal sterol (ergosterol) synthesis- inhibit sterol 14-alpha-demethylase leading to accumulation of 14-alpha-methylsterols and disrupting acyl chains

 

3. Used in systemic mycoses- fluconazole for cryptococcal meningitis in AIDS and all candidal infections; ketoconazole for blasto, coccidio, histo and candida albicans; clotrimazole and miconazole for topical fungal infections

4. Toxicity: gynecomastia by inhibiting hormone synthesis, liver dysfunction (inh P-450), fever, chills

Term
Flucytosine
Definition

1. Fluorinated pyrimidine with antimetabolite fx (deaminated to form 5-FU then converted to 5-FUMP which may be phos and incorporated causing miscoding or 5-FdUMP which is a potent inhibitor of thymidylate synthase)

2. Combined with Amp B for cryptococcus meningitis and other systemic fungal infections

3. primary resistance may occur with candida, C. neoformans and aspergillus due to altered cytosine permease

4. Secondary resistance almost alwasy develops when tx C. neoformans/candida w monotherapy

Term
Caspofungin
Definition

1. Only pneumocandin/echinocandin in US

2. inhibits beta-(1,3)-D-glucan synthase thus inhibiting cell wall synthesis

3. Used in invasive aspergillosis

4. Hypokalemia, GI upset, Histamine release (flushing), phlebitis

 

5. R due to alterations in Beta-(1,3)-glucan synthase binding target

Term
Terbinafine
Definition

1. Allylamine antifungal- Blocks squalene epoxidase inhibiting the formation of ergosterol

2. used to treat dermatophytoses (especially onychomycosis)

3. Toxicity- hepatotoxicity, neutropenia, TEN, steven-johnson syndrome

Term
Griseofulvin
Definition

1. Binds to fungal polymerized MT leading to inhibition of fungal mitosis

2. Deposits in keratin-containing tissues (e.g. nails)

3. Used in oral treamnt of superficial infections- inhibits growth of dermatophytes (tinea, ringworm)

4. Toxicity- teratogenic, carcinogenic, confusion, HA

4. induce metabolism of warfarin and OC (P-450)

Term
Ciclopirox
Definition

1. Anti-Candida and dermatophyte activity

2. Almost no cutaneous toxicity

3. pyridone

Term
iodinated tricholorphenols
Definition

1. Haloprogin

2. tinea vesicolor, candida, dermatophytes

3. skin irritation and exacerbation of lesions

Term
Tolnaftate
Definition

1. dermatophytes

2. less effective than miconazole for tinea pedis

Supporting users have an ad free experience!