Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FM3_ EB > Antiretrovirals > Flashcards

Antiretrovirals Flashcards

1
Q

List two NRTIs

A

zidovudine, abacavir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List an NNRTI

A

efavirenz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List two protease inhibitors

A

ritonavir, atazanavir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

List a membrane fusion inhibitor

A

enfuvirtide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

List an entry inhibitor

A

maraviroc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List an integrase inhibitor

A

raltegravir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Fusion between HIV-1 envelope and the host cell membrane, mediated by viral surface ____ and ____ is essential for entry of HIV into the cell

A

gp120 and gp41

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

HIV must bind to CD4 as well as _____ in order to enter a cell

A

co-receptor, either CCR5 or CXCR4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cleavage of HIV polyproteins by _____ is essential for mature virus formation

A

protease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Enfuvirtide is a peptide that was developed to inhibit a specific region of _____ ap

A

gp41

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Enfuvitide is typically considered _________, meaning it is given to treatment experienced patients who have developed extensive resistance to other agents

A

salvage therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe how resistance to enfuvirtide can arise

A

Mutation in gp41 envelope gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the normal function of gp41

A

Envelope protein; two regions fold upon each other to form a six helix bundle that brings the virus closer to the host cell and is required for membrane fusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the major adverse effect of enfuvirtide?

A

Must be injected 2x daily, leads to injection site reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the mechanism of action of maraviroc

A

Inhibits attachment of viral gp120 to the CCR5 co-receptor on host cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe appropriate use of maraviroc

A

Approved for treatment experienced patients with R5 tropic virus
Will not be effective in patients with X4 or mixed tropism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does resistance to maraviroc arise?

A

Possible to have mutations in gp120 but more likely to have emergence of mixed tropic or X4 tropic virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is unique about maraviroc compared to all other HAART drugs?

A

Something from the host is inhibited instead of something from the virus

19
Q 
List the constituents of common combination drugs:
Combivir
Trizivir
Epzicom
Truvada
A 
Combivir= Lamivudine + Zidovudine
Trizivir= Lamivudine + Zidovudine + Abacavir
Epzicom= Abacavir + Lamivudine
Truvada= Tenofovir + Emtricitabine
20
Q

NRTIs are _____ analogues that lack ____ on the ribose sugar, so when they are incorporated by reverse transcriptase they cause termination of chain elongation

A

nucleoside analogues

3’OH

21
Q

For NRTIs to become active, they must be _______ by host enzymes

A

phosphorylated

22
Q

List three main functions of reverse transcriptase

A
  • synthesizes the - strand of DNA with the viral RNA genome as the template
  • hydrolyzes viral + RNA
  • synthesizes the + strand of DNA
23
Q

List a negative drug interaction that occurs between zidovudine and stavudine

A

Because thymidine kinase (TK) has a higher affinity for zidovudine than stavudine, zidovudine antagonizes the effects of stavudine.

24
Q

Describe two main mechanisms of NRTI drug resistance

A
  • mutations in RT allow the enzyme to discriminate between NRTIs and dTNPs
  • mutations in RT that promote the hydrolytic removal of chain termination NRTIs to allow for continued DNA synthesis
25
Q

True or false: significant cross resistance exists for NRTI drugs

A

True

26
Q

What is one common, class wide adverse effect seen with NRTIs

A

Mitochondrial toxicity and lactic acidosis, hepatic steatosis

27
Q

Describe the mechanism of mitochondrial toxicity caused by NRTIs

A

inhibition of DNA polymerase gamma
leads to a depletion of certain key mitochondrial proteins essential for the electron transport chain leading to a buildup of lactic acid and triglycerides.

28
Q

What specific toxicity is associated with zidovudine?

A

bone marrow suppression

29
Q

What specific toxicity is associated with didanosine?

A

pancreatitis, peripheral neuropathy

30
Q

What specific toxicity is associated with stavudine?

A

peripheral neuropathy

31
Q

What specific toxicity is associated with abacavir?

A

abacavir hypersensitivity syndrome

32
Q

Describe abacavir hypersensitivity syndrome

A

fever, rash, headache, nausea, abdominal pain, cough and shortness of breath
abacavir gets linked onto a protein (ex EtOH dehydrogenase) in APCs, peptide with abacavir on it is bound by HLA-B5701. When this interaction occurs, there is activation of T cells and upregulation of interferon

33
Q

NNRTIs block reverse transcriptase by binding an _________ site on the RT enzyme, inducing a conformational change.

A

allosteric site

34
Q

True or false: Like NRTIs, NNRTIs must be phosphorylized in vivo in order to be active

A

False

35
Q

Describe how resistance to NNRTIs can emerge

A

Mutation in NNRTI binding site, leads to high level resistance against first generation NNRTIs but can usually still use second generation agents
Resistance arises very quickly if NNRTIs are used as monotherapy

36
Q

Describe the positive drug interaction that occurs between NNRTIs and NRTIs

A

some point mutations in RT that confer resistance to NNRTIs may sensitize RT to NRTIs by inhibiting phosphorolysis

37
Q

What class-wide toxicities are seen with NNRTIs?

A

Rash and hepatotoxicity

38
Q

What specific toxicity is associated with efavirenz?

A

CNS effects and teratogenicity

39
Q

Describe the mechanism of raltegravir

A

Integrase inhibitor, docks in the acceptor DNA binding site and interferes with strand transfer

40
Q

Describe the mechanism of action of protease inhibitors

A

Bind to active site o protease and prevent cleavage of gag-pol and blocks viral maturation

41
Q

Why are lopinavir and ritonavir always formulated together?

A

A small dose of ritonavir is used in Kaletra to inhibit Cytochrome P450 CYP3A4 metabolism of Lopinavir and make it a viable drug

42
Q

Describe class wide toxicity seen with protease inhibitors

A

Hepatotoxicity, GI upset, lipodystrophy, insulin resistance highly associated with protease inhibitors

43
Q

What specific adverse reactions are seen with atazanavir?

A

hyperbilirubinemia and QT prolongation

44
Q

Describe the difference between genotypic and phenotypic testing for drug resistance

A

Phenotypic: rate of growth of sample virus compared to wild virus in the presence of drug

Genotypic: sequence of sample compared to wild type virus

FM3_ EB (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions