Anti-fungal Drugs Flashcards Preview

Pharm > Anti-fungal Drugs > Flashcards

Flashcards in Anti-fungal Drugs Deck (67):
1

Which fungi cause superficial mycoses (dandruff, tinea vesicolor)

malessezia globosa, malessezia furfur

2

what fungi cause cutaneous mycoses? (dermathphytosis)

microsporum, trichophyton, epidermophyton

3

what is a cutaneous mycosis called that isn't caused by microsporum, trichophyton, or epidermophyton?

dermatomycosis

4

microsporum, tricophyton, and epidermophyton infect what to cause dermathphytosis

infect skin, hair, nails
metabolize and live off of keratin

5

cutaneous mycoses are often associated with areas of the body that are:

poorly aerated
excessive moisture/sweatuing
tight clothing
high humidity

6

what are some examples of cutaneous mycoses

skin mycoses aka ringworm
tinea corporis
tinea pedis (athletes foot)
tinea cruris (jock itch)
tinea capitis (mycosis of scalp)
tinea barbae (mycosis of beard)
tinea unguium (mycosis of nail, aka onychomycosis)

7

what are the characteristics of subcutaneous mycoses?

chronic, localized
following traumatic implatation with soil fungi
may appear as a small nodule that grows and may drain or ulcerate
can become systemic, especially in immunocompromised

8

what are some examples of subcutaneous mycoses?

sporotrichosis (rose handlers disease)
chromoblastomycosis
mycetona

9

what fungi causes sporotrichosis

sporothrix schenckii

10

what fungi causes chromoblastomycosis

many agents, all dematiacious fungi

11

systemic infections can be either:

dimorphic
opportunistic

12

what are some examples of infections that are considered systemic?

soft tissue
UTI
pneumonia
meningitis
septicemia (in blood)

13

what are the characteristics of systemic mycoses?

entry into host by inhalation of airborne spores
spores germinate in lung
asymptomatic primary pulmonary infection is common
acute pulmonary disease less common
chronic pulmonary or dissemination infection is rare
-can infect immunocompetent or immunocompromised patients
-fungus endemic to a particular region

14

what are the different systemic mycoses that can occur

histoplasmosis
blastomycosis
coccidiomycosis
paracoccidiomycosis

15

blastomyces dermatitidis is endemic to:

mississippi river, ohio river, great lakes

characterized by broad based budding with thick walls that appears double contoured

16

coccidioides immitis is endemic to:

southwest USA
valley fever

appears with arthrospores when grown in lab
-dont want to expose lab workers so often sent away for molecular testing

17

paracoccidiodes brasiliensis is endemic to:

central and south america

90% of symptomatic disease found in males
mariners wheel morphology

18

histoplasma capsulatum is endemic to:

eastern and central USA

19

the opportunistic mycoses are:

candidiasis
cryptococcosis
aspergillosis
mucomycosis
pneumocystis jiroveci

20

what populations have the tendency to be immmunocompromised?

debilitated patients
indwelling catheters
prosthesis
HIV
diabetes or chronic renal, hepatic, cardiac disease
alcoholism

21

describe candidiasis

candida albicans - most common species
overgrowth --> yeast infection
-normally kept under control by normal bacterial flora (almost all infections are endogenous)
lab ID by culture - gram positive, yeast with "feet"
usually occurs in moist areas
-can involve GI tract, kidnesy, liver, spleen, bloodstream, UT, respiratory tract, heart, eye

22

describe mucosal candidiasis

thrush
can be oral, vulvovaginal, esophogeal

23

describe cryptococcus

cryptococcus neoformans

site of infection = lung, meninges, CSF, blood, skin, mucous membranes, systemic
capsules stain pik with mucicarmine
diagnosis with india ink or antigen test* capsule***

24

describe aspergillosis

caused by aspergillus, several species
found in dust, soil, decomising organic matter (environmental)
- spores inhaled and can have a variety of symptoms

25

what does aspergillosis look like in tissue?

septated hypae
branching occurs at 45 degree angles
appears in radial facial, hypae nearly parallel
in cavitary lesions, conidial heads may be observed

26

describe mucomycosis

infection with zygomycete, rhizopus most comon
infection begins in nasal mucosa or sinuses and progresses to the orbit, palate, and brain
-aggressive and rapidly fatal

27

what do zygomycetes look like in tussue

large, nonseptated hypae
ribbon like
branch at 90 degrees

28

Name the antifungal drugs

ampotericin B, nystatin
5-fluorocytosine
ketoconazole, miconazole, clotrimazole
fluconazonle, itraconazole, voriconazole, posaconazole
caspofungin, micafungin, anidulafungin
griesofulvin
terbinafine, butenafine, naftifine
cicliprox, tolnaftate, selenium sulfide

29

what are the seven antifungal drug classes

polyenes
azoles (imidazoles, triazoles)
allylamines
echinocandidins
grisans
pyrimadine
miscellaneous

30

what is the target for polyenes?

ergosterol

31

what is the target for azoles and allylamines

ergosterol biosynthesis

32

what is the target for echinocandidins

cell wall biosynthesis (beta-1,3-glucan synthesis)

33

what is the target for griesans

microtubules

34

what is the target of pyrimidine analogs

DNA synthesis
(permease critical)

35

amphotericin B and nystatin are:

polyenes

36

5FC is:

pyrimidine analog

37

ketoconazole, micronazole, clotrimazole are:

imidazoles

38

fluconazole, itraconazole, voriconazole, posaconazole are:

triazoles

39

caspofungin, micafungin, anidulafungin are:

echinocandidins

40

griesofulvin is:

griesan

41

terbinafine, butenafine, naftifine are:

allylamines

42

cicliprox, tolnaftate, and selenium sulfide are:

miscellaneous antifungals

43

what are the uses for ampho B

drug of choice for must systemic life threatening fungal infections
very broad spectrum
usually given IV

no CNS penetration

44

what are the uses for nystatin

candida, especially thrush (cutaneous mycoses

minimal GI absorption so when taken orally, it only treats GI problems

45

what are the uses for 5FC

used in combination with ampho B to treat candida, cryptococcus, aspergillus (opportunisitic infections)

46

what are the uses for imidazoles
- ketoconazole, micronazole, clotrimazole

broad spectrum against fungi
no CNS penetration
oral and topical
absorption requires an acidic gastric environment (decreased with antacids)
mostly replaced by the triazoles

47

what are the uses for triazoles
-fluconazole, itraconazole, voriconazole, posaconazole

broad spectrum against fungi
better Gi tolerance
inhibits P450
all but itraconazole penetrate the CNS

48

which triazole cannot penetrate CNS

itraconazole

49

what are the uses over echinocandins
-caspofungin, micafungin, anidulafungin

used as a second line after ampho B
newer, expensive
effective against aspergillus, candida

50

what are grisans (griesofulvin) used for

tinea infections
effective against dermatophytes (fungi that metabolize keratin)

51

what are allylamines used for
terbinafine
butenafine
naftifine

treat tinea
topical application
-terbinafine is oral

52

what antifungals have mechanisms that are not well characterized?

cicliprox
tolnaftate
selenium sulfate

53

what is the mechanism of polyenes

amphotericin B
nystatin

forms pores in the membrane by binding to ergosterol causing loss of K and other small molecules

54

what is the mechanism of 5FC

enters fungus using permease (not found in mammals)
converted to 5FU and then incorporated into nucleic acid (pyrimidine analog)

55

what is the mechanism of imidazoles

ketoconazole, microconazole, clotrimazole

inhibits production of ergosterol from lanosterol

56

what is the mechanism of triazoles?

fluconazole, itraconazole, voriconazole, posaconazole

inhibits production of ergosterol from lanosterol

57

what is the mechanism of echinocandins

caspofungin, micafungin, anidulafungin

inhibits cell wall biosynthesis by inhibiting beta-gucan production

58

what is the mechainsm of griesofulvin

inhibits microtubule function, preventing mitosis
binds to keratin in skin and hair making them more resistant to fungal infection

59

what is the mechanism of allylamines

terbinafine, butenafine, naftifine

inhibits ergosterol production via squalene epoxide

60

what are the side effects of amphoB

nephrotoxicity
can make pores in human cells because it also can bind cholesterol to a certain extent

61

what are the side effects of nystatin

makes pores in human cells by binding to cholesterol
highly insoluble, toxic if given IV - topical and oral but minimal GI absorption)

62

what are the side effects of 5FC

bone marrow suppression
GI upset

63

what are the side effects of ketoconazole

inhibits with CYP450, interferes with testosterone and cortisol production
GI upset
hepatic dysfunction

64

what are the side effects of micronazole and clotrimazole

too toxic to give IV but also poorly absorbed as a topical

65

what are the side effect of the triazoles

CYP450 interactions
hepatic dysfunctions
-safer than imidazoles

66

which antifungals have few untoward effects?

echinocandidins
allylamines (headaches and gi upset minor)
driesofulvin has rare but serious adverse effects

67

what rare side effects does griesofulvin have?

hepatotoxicity, GI irritation
bone marrow suppression
headaches