Brainscape's Knowledge GenomeTM

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


See full index

Pharmacology > Antivirals > Flashcards

Antivirals Flashcards

1
Q

What is the process of viral replication

A
  1. Attachment - Haemaglutinin on virus with host cell surface receptor
  2. Uncoating - M2 ion channel H+ influx into virus allows nucleocapsid breakdown
  3. DNA/RNA replication
  4. Protein synthesis
  5. Assembly
  6. Release - Neuraminidase prevents virus adhesion to host cell membrane on release
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are features of antiviral agents

A

Few types of Antiviral agents
Virostatic, not virocidal
Not broad spectrum
Not given empirically

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

What are general mechanisms of action of antiviral agents

A

Virocidal:
Organic solvents, Non-organic solvents, Cryotherapy, Radiotherapy
Not given systematically

Virostatic:
Risk of resistance, not effective in latent infection, requires host immune response to clear existing virus

Immunomodulators:
Enhance host immune (interferons), replace depleted host immune (immunoglobulin)

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

What are the main groups of antiviral agents

A

Anti-herpes virus
Anti-hepatitis virus
Anti-retroviral
Anti-influenza

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

What are types of anti-herpes drugs

A

Aciclovir
Ganiclovir
Foscarnet

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

What is mechanism of action of Aciclovir

A 
Enters virally infected cells
Activated to nucleoside triophosphate by viral Thymidylate Kinase
Incorporated into viral DNA 
Bind to and Inhibit DNA polymerase 
Act as chain terminator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are indications of Aciclovir

A

Herpes simplex encephalitis
Cold sores (HSV1)
Genital ulcers (HSV2)
VZV (chicken pox, shingles >50)

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

What are types of resistance for Aciclovir

A

Viral strains that:
Lack thymidylate kinase
mutation in thymidylate kinase gene
Mutation in DNA polymerase gene that prevents binding with Aciclovir triphosphate

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

What are side effects of Aciclovir

A

Nephrotoxicity

CNS: lethargy, confusion, tremor, hallucination

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

What is mechanism of action of Ganciclovir

A

Same as Aciclovir
But phosphorylation also catalysed by host and viral enzyme (phosphotranserase)
Thus also activated in non infected host cell

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

What are indications for Ganciclovir

A 
CMV infection: 
Colitis
Retinitis 
Pneumonitis 
Pneumonia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are side effects of Ganciclovir

A

Nephrotoxic

Neurotoxic: confusion, headache, behavioural change

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

What is mechanism of action of foscarnet

A

Inhibit binding of nucleoside triphosphate to viral DNA
(Thus does not need to be phosphorylated to be active)

Inhibit HIV reverse transcriptase

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

What are indications of Foscarnet

A

Aciclovir resistant HSV
Ganciclovir resistant CMV
HIV

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

What are side effects of Foscarnet

A

Narrow therapeutic index
GI: N+V, diarrhoea
Nephrotoxicity
CNS: headache, hallucination, tremor, seizure

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

What are types of anti-hepatitis drugs

A 
Lamivudine
Adefovir
Entecavir
Telbivudine
Ribavirin
IFN alpha
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is mechanism of action of Lamivudine

A

Nucleoside Reverse transcriptase inhibitor:
Nucleoside analogue
Gets activated by phosphorylation in cell by nucleoside kinase
Incorporated into viral DNA
Inhibits RT and acts as chain terminator

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

What are indications of Lamivudine

A

Chronic hepatitis B

HIV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is resistance of Lamivudine

A

Common - 67% by 4 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are side effects of Lamivudine

A

Well tolerated

Raised liver enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is mechanism of action of Adefovir

A

Nucleoside Reverse Transcriptase Inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are indications of Adefovir

A

Chronic hepatitis B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the resistance in Adefovir

A

Slow to develop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are side effects of adefovir

A

Well tolerated
GI: nausea, diarrhoea, abdo discomfort
CNS: headache

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is mechanism of action of entecavir

A

Nucleoside RT inhibitor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are indications of entecavir

A

Chronic hepatitis B

Lamivudine-resistant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is resistance in entecavir

A

No reported resistance

28
Q

What are side effects of Entecavir

A

GI: nausea, diarrhoea
CNS: headache, dizziness, photosensitivity

29
Q

What is mechanism of action of Telbivudine

A

Potent NRTI

30
Q

When is telbivudine indicated

A

Chronic hepatitis B

When other treatments failed

31
Q

What is mechanism of action of Ribavirin

A

Inhibit RNA synthesis

32
Q

When is Ribavirin indicated

A

Hepatitis C

33
Q

What are side effects of Ribavirin

A 
Anaemia (extravascular haemolysis)
Myelosupression 
Myalgia 
Pruritus
Rash
Anxiety
34
Q

What is mechanism of action of Interferons

A

Enhance cell-mediated immune response
Increased activation of NK cells, macrophages
IFNs are cytokines released by Th1 cells when infection by intracellular pathogen occurs

35
Q

What are indications of IFN therapy

A

Hepatitis B

Hepatitis C

36
Q

What are side effects of IFN therapy

A 
Flu-like symptoms:
Fever
Chills
Malaise 
Headache
GI
37
Q

What are types of anti-influenza drugs

A

M2 ion channel inhibitors

Neuraminidase inhibitors

38
Q

Give examples of M2 ion channel inhibitors

A

Amantadine

Ramitidine

39
Q

What is mechanism of action of M2 inhibitors

A

Inhibit proton influx into virus
Inhibit pH mediated uncoating of virus
Thus inhibit viral replication

40
Q

What are indications of M2 ion channel inhibitors

A

Influenza A

41
Q

What are side effects of M2 ion channel inhibitors

A

Low dose: nervousness, confusion, insomnia

High dose: delirium, hallucination, seizure

42
Q

Give examples of neuraminidase inhibitors

A

Oseltavir (Tamiflu)

Zanamivir

43
Q

What is mechanism of action of Neuraminidase inhibitors

A

Inhibit breaking of bond bw virus and host cell membrane

Inhibit release of virus from infected host cell

44
Q

What are indications of neuraminidase inhibitors

A

Influenza A + B
Oseltavir: treatment and prophylaxis
Zanamivir: treatment only

45
Q

What is process of HIV replication

A
  1. Attachment - to CD4+ on T cells
  2. Uncoating
  3. Reverse transcription - reverse transcriptase
  4. vDNA integration- integrase
  5. Transcription
  6. Replication
  7. Assembly + budding
  8. Maturation - proteases in new virion
46
Q

What are types of antiretroviral drugs

A

Nucleoside Reverse Transcriptase Inhibitor
Non-Nucleoside Reverse Transcriptase inhibitor
Protease inhibitor
Fusion inhibitor

47
Q

Give examples of NRTIs

A

Lamivudine

Zidovudine

48
Q

What are indications of NRTIs

A

HIV 1

HIV 2

49
Q

What is resistance in NRTIs

50
Q

What are side effects of NRTIs

A

Hyperlactataemia
Lactic acidosis
Hepatomegaly

51
Q

What are examples of NNRTIs

A

Nevirapine

Delavirdine

52
Q

What is mechanism of action of NNRTI

A

Allosteric inhibition of RT

53
Q

What are indications of NNRTI

A

HIV 1

Can be combined with NRTI (binding site on RT different )

54
Q

What are side effects of NNRTI

A

Raised LFTs
Dizziness, sleep disturbance, headache
Rash
Erythematous maculopapular rash

55
Q

Give examples of protease inhibitors

A

Saquinavir

Ritonavir

56
Q

What is mechanism of action of protease inhibitors

A

Inhibit protease activity in new virion - cleavage of polyprotein into mature proteins
Inhibit maturation

57
Q

What are indications of protease inhibitors

A

HIV 1

HIV 2

58
Q

What are side effects of protease inhibitors

A 
Inhibit CYP450
Hypercholesterolaemia
Hyperglycaemia
Increased risk of MI
Osteoporosis, osteopenia, osteonecrosis
59
Q

Give examples of fusion inhibitors

A

Enfuvirtide

60
Q

What is mechanism of action of fusion inhibitor

A

Inhibit HIV binding to CD4 receptors on T cells

61
Q

What are indications of Fusion inhibitors

A

HIV 1

When other combinations failed

62
Q

What are side effects of Fusion inhibitors

A

Injection site reaction: pain, induration, erythema, cysts
Hypersensitivity rash
Fever
Hypotension

63
Q

Why do you need to do antiviral resistance testing

A

Optimise patient outcomes
Save costs
Reduce pool of drug-resistant virus

64
Q

When is antiviral resistance testing indicated

A

Rising viral load despite good compliance
Rising viral load in Poor compliance
Newly diagnosed patients

65
Q

How is antiviral resistance testing carried out

A

Incubate suspected resistant viral strain with drug

Compare response with normal viral strain

66
Q

What does low barrier to response mean

A

Only need few mutations to develop antiviral resistance

67
Q

What does ‘unfit’ virus mean

A

Mutation that causes antiviral resistance also has negative impact on virus ability to replicate
Thus virus strain cannot survive

Pharmacology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions