Antiviral Agents

Question 1

What is acyclovir effective against?

Answer 1

herpes simplex 1,2 and herpes zoster virus

Question 2

What does acyclovir convert?

Answer 2

To monophosphate acyclo-GMP by viral thymidine kinase, then to triphosphate by a cellular enzyme

Question 3

How does acyclovir work?

Answer 3

The triphosphate formed inhibits DNA polymerase through chain terminations

Question 4

How is acyclovir administered?

Answer 4

Topically
Orally
IV

Question 5

How are some adverse effects of acyclovir?

Answer 5

psychiatric = Cotards

Toxicity if overdose = lethargy, confusion, myoclonus

Question 6

What is the difference between valacyclovir and acyclovir?

Answer 6

Vala is acyclovir esterified to valine

greater oral bioavilability

Question 7

How does resistance to acyclovir and valaciclovir occur?

Answer 7

Mutation of viral thymidine kinase and/or DNA polymerase

Question 8

What is idoxuridine used for?

Answer 8

Topically only = herpes keratitis

- too toxic for systemic use

Question 9

What are ganciclovir and valganciclovir against?

Answer 9

Active CMV

Question 10

What is acyclovir an analogue of?

Answer 10

Guanosine

Question 11

What is ganciclovir an analogue of?

Answer 11

Deoxyguanosine

Question 12

What does ganciclovir do?

Answer 12

Phosphorylated to monophosphate by CMB thymidine kinase then to triphosphate by cellular kinases

Question 13

How does ganciclovir work?

Answer 13

Inhibits viral DNA polymerase by acting as a chain terminator

Question 14

What is the difference between valganciclovir and ganciclovir?

Answer 14

Valine ester of it

Greater oral bioavailability

Question 15

What are the adverse effects of valganciclovir and ganciclovir?

Answer 15

Adverse effects such as bone marrow suppression

Question 16

Which drugs are effective against herpes?

Answer 16

foscarnet
acyclovir
valacyclovir
ganciclovir
valgancyclovir

Question 17

Which drugs are reverse transcriptase inhibitors?

Answer 17

Nuceloside and nucleotide analgoues (NRTIs)

• nuceloside analogues = zidovudine, lamivudine
• nucleotide analogues = tenofovir

Question 18

What do NRTIs do?

Answer 18

inhibit reverse transcriptase by incorporating into growing DNA chain and not linking subsequent base

Question 19

Adverse effects of zidovudine?

Answer 19

GI, haem, headache, hepatotoxic, cardiomyopathy

Question 20

Adverse effects of lamivudine?

Answer 20

nausea, fatigue, headache, diarrhoeaa, cough, pro-inflamm response, autoimmunity

Question 21

Adverse effects of tenofovir?

Answer 21

renal insufficiency

Fanconi syndrome

Question 22

What do NNRTIs do?

Answer 22

Non-nucleoside/tide reverse transcriptase inhib

- bind to reverse transcriptase enzyme not at active site and distort it

Question 23

Examples of NNRTIs?

Answer 23

• nevirapine

Question 24

What are some adverse effects of nevirapine?

Answer 24

hepatitis

Stevens-Johnson

Question 25

What do protease inhibitors do?

Answer 25

Bind to viral protease which cuts viral precursor proteins into virion structure parts

Question 26

Examples of protease inhibitors?

Answer 26

Saquinavir Indinavir Ritonavir

Question 27

What are some adverse effects of Saquinavir?

Answer 27

GI, rash, neuro, metabolic, QT prolonged

Question 28

What do integrase inhibitors do?

Answer 28

Inhibit integrase which is a viral enzyme for HIV DNA integration into host genome

Question 29

What do fusion inhibitors do?

Answer 29

Block gp41 on surface of HIV virion which mediates fusion between HIV envelope and cell membrane

Question 30

What do entry inhibitors do?

Answer 30

Block CCR5 (chemokine) receptor on cell surface which with CD4 enables gp120 on HIV surface to bind and enter

Question 31

What is ribvarin an analogue of?

Answer 31

Guanosine | Ribo-nucleoside

Question 32

How does ribvarin work?

Answer 32

Inhibits viral RNA dependent RNA polymerase so terminates chain

Question 33

What does ribvarin do?

Answer 33

Against hep C, viral haemorrhagic fevers, resp syncytial virus Influenza

Question 34

What are adverse effects of ribvarin?

Answer 34

Haemolytic anaemia Bone Marrow suppression Depression Cough

Question 35

Which drugs are effective against retroviruses?

Answer 35

``` NRTIs NNRTIs Protease inhibitors Integrase inhibitors fusion inhibitors entry inhibitors ribvarin ```

Question 36

How does neurominidase inhibitors work?

Answer 36

viral neurominidase cleaves siliac acid release virion from host cell, - aggregation of virions, - viral inactivation by host mucus

Question 37

Examples of neurominidase inhibitors?

Answer 37

Oseltamivir | Zanamivir

Question 38

How do M2 inhibitors work?

Answer 38

Inhibit M2 protein of virus to decrease hydrogen ion influx | Inhibits upcoating and recoating

Question 39

Examples of M2 inhibitors?

Answer 39

Amantidine | Rimantadine

Question 40

Which drugs are used in influenza treatment

Answer 40

Ribvarin Neurominidase inhibtiors M2 inhibtiors

Question 41

Which drugs treat Hep C?

Answer 41

``` Protease Inhibitors (DAA) NSSA Inhib NSSB Inhib Ribvarin Pegylated interferon ```

Question 42

What do DAA do?

Answer 42

Direct acting agents | Inhibit viral NS3/4A serine protease

Question 43

Examples of DAAs?

Answer 43

Telaprevir

Question 44

What is NSSA?

Answer 44

Viral protein enabling assembly

Question 45

Example of NSSA inhib?

Answer 45

Ledipasvir

Question 46

What does NSSB inhib do?

Answer 46

Inhibits Viral RNA polymerase

Question 47

Examples of NSSB inhib?

Answer 47

Sofosbuvir | Dasabuvir

Question 48

What does PEGylated interferon do?

Answer 48

Interferon alpha or beta | Human cytokines enhancing immune response

Question 49

What does PEGylated mean?

Answer 49

Linked to poly-ethylene glycol to prolong half life

Question 50

Which drugs are used in hep B treatment?

Answer 50

Reverse transcriptase inhibitors Iamivudine Tenfovir Interferon pegylated

Question 51

What drugs are used for resp syncytial virus?

Answer 51

Monoclonal antibody against RSV fusion glycoprotein (palvizumab) Ribvirine (inhaled)

Question 52

What are the stages of the viral replication cycle from entry to release?

Answer 52

- docking on - escape from the vacuole - replication of DNA/RNA - integration of DNA into genome - assembly of virions - escape from host cell