Chapter 18: non-bacterial infections Flashcards Preview

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Flashcards in Chapter 18: non-bacterial infections Deck (123):
1

 

 

what has extensive use of ABTs worldwide led to?

 

 

emergence of viral and fungal superinfections

2

 

 

What population is most affected by superinfections

 

 

immunocompromise

3

 

 

effective, specific agents are often based on

 

 

genetic sequencing and understanding of pathogens

4

 

 

how does a virus reproduce

 

 

enters a host cell and take over the cell's protein and nucleic acid synthesis

5

 

 

effective antiviral agents need to stop one of the steps in the viral replication process

 

 

attachment of the virus to the host cell -release of the virus's genes into the host cell

replication and assembly of new viral components -release of viral components into a new host cell

6

 

 

regimen of medications used to treat HIV

 

 

highly active antiretroviral therapy (HAART)

7

 

 

clinical syndrome review of HIV/AIDS

 

 

"clinical syndrome"

opportunistic infections

cancer

"set point"

8

 

 

HIV replication

 

 

reverse transcribe RNA genome into DNA thus reversing the usual flow of genetic information. DNA is then incorporated into host cell's genome allowing replication

9

 

 

reasons for noncompliance with HIV treatment regimen

 

 

length of treatment, side effects, cost of medications,

10

 

 

Patient education regarding HAART treatment

how to take med

adverse effects

fitting regimen into lifestyle longterm

cost management

safe sex practices

avoiding opportunistic infections

how to live with chronic infectious disease

11

 

 

purpose of antiretrovirals in HIV treatment

 

 

combination of drugs to suppress viral replication to undetectable plasma HIV RNA to prevent further immune system damage as well as any possibility of emergingresistant strains

12

 

 

6 classes of antiretrovirals

 

NRTI

NNRTI

PI

CCRS

FI

INTEGRASE

13

 

 

most common combinations of antiretrovirals for treatment of HIV

 

 

NRTI with PI one NNRTI

14

 

 

initial antiretroviral regimen consist of

 

 

2 NRTIs with with either an NNRTI, PI, Integrase inhibitor, or CCR5 antagonist

15

 

 

examples of NRTIs

 

abacavir (Ziagen)

didanosine (Videx)

emtricitabine (Emtriva)

 lamivudine (Retrovir)

zalcitabine (Hivid)

stavudine (Zerit)

16

 

 

NRTIs are synthetic agents thast mimic

 

 

natural nucleotides (building blocks of RNA)

17

 

 

NRTI mechanism of action

 

 

compete with natural nucleotides in the HIV virus that would otherwise be used in the reverse transcriptase enzyme in newly synthesized viral DNA chains

18

 

 

common adverse effects of NRTIs

rash

abdominal distress

thrombocytosis

 fatigue

lactic acidosis

back pain

tremor, headache, weakness

19

 

 

things to watch for with NRTIs

 

 

leukopenia, anemia, anaphylaxis, heptomegaly

20

 

 

concomittent use of any 2 NRTIs

 

 

not recommended

21

 

 

labs that need monitored with antiretroviral treatment

 

CBC

met panal

CD4

lymphocytes

 HIV levels

22

 

 

what else should HIV patients be tested for prior to initiating therapy

 

 

Hep B

23

 

 

patients on abacavir must be monitored for

 

 

signs of hypersensitivity and elevated liver function

24

 

 

target of PIs

 

 

later stage in viral replication cycle than NRTIs

25

 

 

PI mechanism of action

 

 

bind to active sites that are used by viral protease enzymes so they can't process viral precursors critical to the maturation of an HIV virus

26

 

 

examples of PPIs

amprenavir (Agnerase)

atazaniavir (ATV, Reyataz)

fosamprenavir (Lexiva, Telzir)

indinavir (Crixivan)

ritonavir (Norvir)

saquinavir (Fortovase)

nelfinavir (Viracept)

27

 

 

hypersensitivity reactions of PIs

 

 

can be severe

28

 

 

interactions with drugs metabolized in the liver that can cause serious life threatening events

nonsedating antihistamines

sedative hypnotics

Astemizole, triazolam, midazolam

ergot alkaloid preparation

antiarrhythmics (amiodarone, quinidine)

CCBs

amphetamines

29

 

 

PI contraindications

 

 

hypersensitivity to sulfonamides

patients taking vitamin E

30

 

 

NNRTI mechanism of action

 

 

bind to active site of HIV reverse transcriptase

is additive or synergistic with most other antiretrovirals

31

 

 

examples of NNRTIs

 

delavirdine (Rescriptor)

evavirenz (Sustiva)

nevirapine (Viramune)

32

 

 

DERM side effect of NNRTIs

 

 

rash that progresses to epidermal necrosis

33

 

 

NNRTIs patient education

 

 

stay well hydrated to avoid renal failure

34

 

 

why should efavirenz be taken at bedtime

 

 

improve CNS tolerability and psychiatric effects

35

 

 

what follows initial herpes infection

 

 

latent state with the potential to reactivate later in life

36

 

 

efficacy of episodic therapy for herpes

 

 

shortens the duration of an outbreak if started within 24 hours of lesions or prodromal symptoms

37

 

 

mechanism of action for antivirals used for herpes infections

 

 

nucleic acid analogues host enzymes cause them to convert to active compounds and become part of the DNA chain. This inhibits viral RNA to interferen with viral DNA synthesis

38

 

 

examples of antivirals used to treat herpes infections

acyclovir (Zovirax)

cidofovir (Vistide)

ganciclovir (Cytovene)

famciclovir (Famvir)

penciclovir (Denavir)

foscarnet (Foscavir)

trifluridine (Viroptic)

valacyclovir (Valtrex)

valganciclovir (Valcyte)

39

 

 

interactions with antivirals used for herpes infections

 

 

minimal.

May affect bioavailability if acyclovir anf famciclovir are given with antihistamines

40

 

 

most important variable in selecting antiviral for herpes treatment

 

 

renal function

41

 

 

examples of antivirals used for respiratory infections

 

amantadine (Symmetrel)

oseltamivir (Tamiflu)

rimantadine (Flumadine)

zanamivir (Relenza)

42

 

 

zanamivir (Relenza) mechanism of action

 

 

prevents viral replication by inhibiting the enzyme neuraminidase

43

 

 

amantadine (Symmetrel) mechanism of action

 

 

dopaminergic agonsit with the ability to block the uncoating of influenza A virus

44

 

 

rimantadine (Flumadine) mechanism of action

 

 

tricyclic amine that affects the release of newly replicated virus strands from host cells, possibly by inhibiting uncoating of the virus

45

 

 

osteltamivir (Tamiflu)

 

 

analogue of sialic acid and is potent selective inhibitor of influenza A and B virus neuraminidase

46

 

 

clinical use for osteltamivir and zanamivir

 

 

prevention and treatment of influenza A or B

47

 

 

clinical use for amantadine and rimantadine

 

 

prevention and treatment for influenza A

48

 

 

susceptibility of vast majority of H1N1 strains

 

 

susceptible to osteltamivir and zanamivir

 resistant to amantadine and rimantadine

49

 

 

antivirals for respiratory infections administered with antihistamines or antidepressants

 

 

cause dry mouth, blurry vision, and constipation

50

 

 

what drug causes increased toxicity if given with amantadine and rimantadine

 

 

triamterine

51

 

 

contraindications for amantadine and rimantadine

 

 

pregnancy

52

 

 

types of antifungals

 

polyene macrolides

azoles

terbinafine (Lamisil)

griseofluvin (Fluvicin)

53

 

 

examples of polyene macrolides

 

 

amphotericin B

Nystatin

54

 

 

examples of Azoles

 

 

imidazole

triazole

55

 

 

patient education on antivirals used for respiratory infections

 

 

only shortens flu duration by 1-2 days

alcohol compounds dizziness

take 4 hours prior to bed to avoid insomnia

56

 

 

drug of choice for topical fungal infections

 

 

nystatin

57

 

 

clinical uses of amphotericin B

 

cryptococcal meningitis in HIV patients

invasive and rapidly progressing, potentially fatal fungul infections

treatment of visceral leishmaniasis

58

 

 

polyene macrolides mechanism of action

 

 

bind to sterols in the fungal cell membrane altering the membranes permeability to K+, Mg+, and other celll components

59

 

 

polyene macrolide interactions

 

 

synergistic nephrotoxicity with aminoglycosides or cyclosporine

60

 

 

patient education about polyene macrolides

 

 

long term treatment may be necessary to clear infection (weeks to months)

61

 

 

azoles mechanism of action

 

 

inhibits fungal demethylase (a CYP450 dependent enzyme present in fungi) affects the synthesis of the fungal cell wall and causes leakage of cell contents

62

 

 

types of azoles

 

 

imidazole

triazole

63

 

 

examples of imidazoles

 

 

fluconazole (Diflucan)

ketoconazole (Nizoral)

itraconazole (Sporanox)

64

 

 

clinical uses of oral antifungals

 

 

superficial infections caused by yeast

dermatophytes, and invase systemic mycoses (page 351)

65

 

 

clinical uses for topical antifungals

 

 

treat tinea infections and superficial yeast infections

66

 

 

which antifungal should NOT be used with history of HF

 

 

itraconazole

67

 

 

why should coadministration of ABTs and azoles be avoided

 

 

 

 

can lead to fungal resistance and fungal superinfection

68

 

 

patient education: itraconazole

 

 

take with food to enhance absorption

avoid antacids within 2 hours of ingestion

69

 

 

terbinafine (Lamisil)

mechanism of action

 

 

synthetic allylamine that inhibits squalene 2, 3-epoxidase

(enzyme needed for cell wall synthesis)

fungicidal to a wide variety of dermatophytes

70

 

 

clinical uses for lamisil

 

 

superficial fungal infections of hair, nail, and skin

examples:

tinea pedic (athletes foot)

tinea cruris (jock itch)

tinea corporis (ringworm)

71

 

 

lamisil interactions

 

 

alcohol increases liklihood of hepatotoxicity

drugs that inhibit hepatic metabolism (cimetidine, rifampin)

caffeine can increase side effects

72

 

 

patient education for lamisil

 

notify clinician if dark urine, rash, pale stool appear

take same time every day for entire course

discuss OTC and herbal medications prior to use

73

 

 

griseofulvin (Fulvicin)

mechanism of action

 

 

binds to microtubules that comprise the spindles to inhibit fungal mitosis

fungistatic

74

 

 

what is griseofulvin NOT used for

 

 

subcutaneous or deep fungal infections

candidiasis

tinea versicolor

75

 

 

clinical uses of fluvicin

 

 

treatment of superficial fungal infections of hair, nails, and skin

76

 

 

griseofulvin interactions

 

 

reduces plasma salicylate levels when taken with ASA

oral contraceptives

reduces anticoagulant effect of warfarin

can increase effects of alcohol (tachycardia, diaphoresis, flushing)

77

 

 

griseofulvin contraindications

 

 

severe liver disease

active alcoholism

pregnancy

78

 

 

most common adverse effect of griseofulvin

 

 

 

 

skin eruptions and rash, sore throat

79

 

 

types of antiprotozoals

 

metronidazole (Flagyl)

nitazoxanide (Alinia)

tinidazole (Tindamax)

80

 

 

conscientious prescribing of antiprotozoals

 

 

include sexual partner in treatment for trichomoniasis

disulfiram-like reaction can occur to alcohol base in other preparations

efficacy unknown in immunocompromised patients

81

 

 

what should be done if antiprotozoal re-treatment is necessary

 

 

CBC

white blood cell differential

82

 

 

antiprotozoal patient education

 

 

avoid alcohol for at least 24 hours after last dose

expect metallic taste

may cause reddish-brown urine

take with food to avoid GI upset

83

 

 

metronidazole (Flagyl) 

mechanism of action

 

 

anaerobic bactericide, trichomonacide, amebicide

diffuses into a susceptible organisma and disrupts DNA and protein synthesis

84

 

 

clinical use of flagyl

 

 

oral therapy for anaerobic infections, amebiasis, giardiasis, trichomoniasis, and colitis d/t C-diff

85

 

 

nitazoxanide (Alinia)

mechanism of action

 

 

interferes with the pyruvate ferrodoxin enzyme pathway

86

 

 

clinical uses of nitazoxanide (Alinia)

 

 

diarrhea associated with Giardia lamblia and Cryptosporidium parvum

87

 

 

tinidazole (Tindamax)

mechanism of action

 

 

similar to flagyl but is converted to an active metabolite by cell extracts of the pathogen

88

 

 

clinical uses for tinidazole (Tindamax)

 

 

intestinal amebiasis, giardiasis, and trichomoniasis

89

 

 

clinical uses of antiprotozoals

 

 

topically for rosacea and bacterial vaginosis

used in combo therapy for H. pylori ulcers

90

 

 

antiprotozoal interactions

 

 

flagyl and warfarin may induce bleeding

cimetidine may decrease metabolism of flagyl

disulfram-like reaction with alcohol

91

 

 

antiprotozoals contraindications

 

 

first trimester of pregnancy

lactation

92

 

 

antihelminthics

 

 

used to treat parasitic infections

93

 

 

classes of antihelminths

 

 

benzimidazoles

pyrantel pamoate

ivermectin

94

 

 

axamples of benzimidazoles

 

 

mebendazole (Vermox)

thiabendazole (Mintezol)

albendazole (Albenza)

95

 

 

appropriate treatment for all helminthic infestations except pinworms

 

 

mebendazole 100mg BID x 3days

OR

albendazole 400mg daily

96

 

 

most pressing concern when fighting a nematode infestation

 

 

seeing resistance develop

monitor patients closely

97

 

 

why should patients be monitored closely when taking a banzimidazole

 

 

propensity of medication to cause bone marrow depression, aplastic anemia, or agranulocytosis

98

 

 

benzimidazoles mechanism of action

 

 

each act directly on different parasites to treat systemic infections

99

 

 

uses for mebendazole (Vermox)

 

 

treatment of ascariasis, trichuriasis, hookworm, and pinworm infections

100

 

 

uses of thiabendazole (Mintezol)

 

 

treatment of strongyloidiasis (threadworm)

101

 

 

uses of albendazole (Albenza)

 

 

treatment of ascariasis enterobiasis (pinworm), hookworm, and after surgical removal or aspiration of hydatid cysts

102

 

 

antihelminths interactions

 

 

mebendazole metabolism is inhibited by cimetidine and anticonvulsants

thiabendazole and xanthine derivatives can cause toxicity

103

 

 

antihelminths contraindications

 

 

pregnancy

renal disease

cirrhosis

 

104

 

 

antihelminths patient education

 

 

chew tablets before swallowing

stool should be rechecked 3 days after treatment

strict hygiene to prevent reinfection

105

 

 

pyrantel pamoate

mechanism of action

 

 

acts as a neuromuscular blocking agent in susceotible mature and immature helminths within the GI tract

106

 

 

pyrantel pamoate is only effective where

 

 

within the GI lumen

107

 

 

clinical uses of pyrantel pamoate

 

 

pinworm, roundworm, hookworm

108

 

 

pyrantel and piperazine

 

 

mutually antagonize each other

109

 

 

ivermectin (Stromectol)

mechanims of action

 

related to macrolide ABTs

causes paralysis and death of parasite by binding to chloride channels in parasite's nerve and muscle cells

110

 

 

clinical uses of ivermectin

 

 

river blindness (Onchocera volvulus)

control of head lice and scabies

 

111

 

 

ivermectin interactions

 

 

can affect LFTs

barbituates and benzodiazepines can cause increased sedation

112

 

 

ivermectin contraindications

 

 

pregnancy

lactation

113

 

 

drugs used to treat malaria

 

 

chloroquine

primaquine

atovaquone/proguanil (Malarone)

114

 

 

chloroquine mechanism of action

 

 

interfers with parasite protein synthesis and inhibits it's growth

115

 

 

what is the most widely used drug to treat malaria

 

 

chloroquine

(prophylaxis and treatment)

116

 

 

mechanism of action for primaquine and mefloquine

 

 

destroy the asexual blood forms of malarial pathogens 

inhibits parasite growth

117

 

 

when are primaquine and mefloquine used

 

 

when there is known resistance to chloroquine

118

 

 

malarone use

 

 

malria prophylaxis

119

 

 

antimalarial drugs when patient is on cardiac medications such as beta-blockers

 

 

take cardiac medication at least 12 hours after antimalarial

120

 

 

contraindications for antimalarials

 

 

history of seizures, psychiatric disorders, cardiac abnormalities

pregnancy

121

 

 

lab values that require d/c of antimalarial medication

 

 

drop in LFTs, HGB concentrations, or leukocyte counts

122

 

 

antimalarials in patients with G6PD

 

 

watch for hemolytic anemia or leukopenia

123