Partial 2 (Anti-fungal Drugs)

Question 1

Polyene antibiotics ________, ________ increase the permeability of the fungal cell membrane.

Answer 1

______ _______ amphotericin B, nystatin

increase the ______ of the _____ _____membrane.

Question 2

________ antibiotics (amphotericin B, nystatin) increase the _______ of the _______ _____ membrane.

Answer 2

Polyene antibiotics (amphotericin B, nystatin) increase the permeability of the fungal cell membrane.

Question 3

Polyene antibiotics

Define:

MOA:

Name 3 ex:

Answer 3

class of antimicrobial polyene compounds that target fungi

• typically obtained from Streptomyces bacteria.
• bind to ergosterol in the fungal cell membrane and weakens i*_t, causing _*leakage of K+ and Na+ ions, which may contribute to fungal cell death. Amphotericin B, nystatin, and natamycin are examples of polyene antimycotics.

They are a subgroup of macrolides.

Question 4

Azole derivatives* and *allylamine drugs

inhibit what?

Answer 4

Azole derivatives and allylamine drugs

inhibit synthesis of plasma membrane ergosterol,

and

caspofungin inhibits cell wall glucan synthesis.

Question 5

____ _____ and _____ drugs inhibit synthesis of plasma membrane ergosterol, and caspofungin inhibits cell wall glucan synthesis.

Answer 5

Azole derivatives and allylamine drugs

_____ _____ of plasma membrane _______, and _____ inhibits ____ ____ ____ synthesis.

Question 6

ergosterol

Define:

Answer 6

• Ergosterol is a biological precursor of vitamin D2, -Exposure to ultraviolet light causes a photochemical reaction that converts ergosterol to ergocalciferol.
• a sterol found in cell membranes of fungi and protozoa, serving many of the same functions that cholesterol serves in animal cells.
• Because many fungi and protozoa cannot survive without ergosterol, the enzymes that synthesize it have become important targets for drug discovery.

In human ergosterol is a provitamin form of vitamin D2; exposure to ultraviolet (UV) light causes a chemical reaction that produces vitamin D2.

Question 7

caspofungin

Define:

Answer 7

new class of antifungals termed the echinocandins.

MOA: It works by inhibiting the enzyme (1→3)-β-D-glucan synthase and thereby disturbing the integrity of the fungal cell wall.

Caspofungin was the first inhibitor of fungal (1→3)-β-D-glucan synthesis to be approved by the United States Caspofungin is administered intravenously.

Question 8

Flucytosine is converted to_____ by ___ ____

and is then incorporated into fungal RNA, where it inhibits _____ ______.

Answer 8

__________ is converted to 5-FU by fungal cells

and is then incorporated into ___ ____, where it inhibits protein synthesis.

Question 9

Flucytosine is used in combination with

________ ___ for cryptococcal meningitis and ________.

Answer 9

__________ is used in combination with amphotericin B for ______ _______

and candidiasis

Question 10

Amphotericin B is used to treat severe _____ and _______ _______, but it often causes chills, fever, nephrotoxicity, and other adverse effects.

Answer 10

_______ ____ is used to treat severe systemic and subcutaneous mycoses, but it often causes ____, _____ , ______, and other adverse effects.

.

Question 11

Lipid formulations have _____ _____ and similar ______ compared with nonlipid formulations

Answer 11

_____ _____ have less toxicity and similar efficacy compared with ______ formulations

Question 12

Several _____ _____ are used to treat systemic mycoses.

Answer 12

Several azole derivatives are used to treat _____ _____.

Question 13

_______ can be used to treat blastomycosis, coccidioidomycosis, histoplasmosis, and sporotrichosis.

Answer 13

Itraconazole can be used to treat ______ , _____ , ________ , and _______.

Question 14

________ is used to treat candidiasis and cryptococcosi

Answer 14

Fluconazole is used to treat ______ and _______

Question 15

Voriconazole and caspofungin are used to treat invasive _____ and ______.

Answer 15

_________ and ______ are used to treat invasive candidiasis and aspergillosis.

Question 16

Caspofungin inhibits the synthesis of a _____ cell wall component, β-(1,3)-D- glucan.

Answer 16

________ inhibits the synthesis of a fungal cell wall component, _______ -glucan.

Question 17

Superficial Candida infections can be treated with

_______, ______ _____, or ______.

Answer 17

______ _______ infections can be treated with nystatin, azole derivatives, or ciclopirox

Question 18

Dermatophyte infections or the ____can be treated by topical or ____ ______ of an _____ derivative

or; terbinafine by oral administration of ________; or by topical administration of _____, ______, or ______

Answer 18

________ infections or the skin can be treated by _____ or oral administration of an azole derivative or; _______ by ____ administration of griseofulvin; or by _____administration of ciclopirox, naftifine, or tolnaftate

Question 19

Itraconazole and terbinafine are given _____ to treat _______, whereas efinaconazole is a ______ agent for this infection.

Answer 19

________ and _______ are given orally to treat onychomycosis, whereas _______ is a topical agent for this infection.

Question 20

Griseofulvin interferes with ______ ______ and blocks _____. It is given orally in treating tinea capitis and other dermatophyte infections.

Answer 20

_______ interferes with microtubule function and blocks mitosis. It is given _____ in treating ______ ______ and other _______ infections.

Question 21

Subcutaneous mycoses

define:

Answer 21

_______

less common than superficial fungal infections

• characterized by a heterogeneous group of infections that often result from direct penetration of the fungus into the dermis and subcutaneous tissue through traumatic injury. -The fungus spreads by local deep tissue invasion from the inoculation site.
• The disease usually remains localized and then slowly spreads to adjacent tissue and eventually to the lymphatics. -More rarely, hematogenous dissemination is observed.

Question 22

Streptomycetes

Define

Answer 22

The antibiotic streptomycin takes its name directly from Streptomyces.

They produce over two-thirds of the clinically useful antibiotics of natural origin (e.g., neomycin, cypemycin, grisemycin, bottromycins and chloramphenicol)

Streptomycetes are infrequent pathogens, though infections in humans, such as mycetom

Question 23

Dermatophytes

Define:

Answer 23

Dermatophytes (Greek- derma “skin” dermatos) and phyton “plant”) are a common label for a group of three types of fungus that commonly causes skin disease in animals and humans.

These anamorphic (asexual or imperfect fungi) mold genera are: Microsporum, Epidermophyton and Trichophyton.

Dermatophytes cause infections of the skin, hair, and nails, obtaining nutrients from keratinized material.

The organisms colonize the keratin tissues causing inflammation as the host responds to metabolic byproducts. Colonies of dematophytes are usually restricted to the nonliving cornified layer of the epidermis because of their inability to penetrate viable tissue of an immunocompetent host