Anti-virals

Question 1

What drugs are used for influenza A & B?

Answer 1

Oseltamivir (tamiflu)

Zanamivir

Question 2

Give examples of herpes infections

Answer 2

Cold sores
Encephalitis
Genital infections

Question 3

Describe the treatment for herpes

Answer 3

Aciclovir
Cidofovir
Foscarnet

Question 4

What drugs are given for cytomegalovirus?

Answer 4

Ganciclovir (prophylaxis in transplant patients)
Foscarnet
Cidofovir (resistant cases)

Question 5

What drugs are used for HIV?

Answer 5

Combination of:

Nucleoside reverse transcriptase inhibitor (NRTI)

AND

Nuceloside reverse transcriptase inhibitor (NRTI)

AND (one of the following)

Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Protease inhibitor
Integrate inhibitor
CCR5 (entry) inhibitor

Question 6

Give an example of an NRTI

Answer 6

Lamivudine

Zidovudine

Question 7

Give an example of an NNRTI

Answer 7

Nevirapine

Question 8

What are the drugs used for hepatitis B?

Answer 8

Lamivudine
Interferon alpha
Adefovir

Question 9

What drugs are used for hepatitis C

Answer 9

Sofosbuvir
Interferon alpha
Ribavirin (chronic) with interferon alpha

Question 10

What is the mechanism of action of oseltamivir/zanamivir? (Treats influenza)

Answer 10

Neuroaminidase inhibitor

Blocks release of newly assembled influenza virons from host cell

Question 11

What is the mechanism of action of aciclovir?

Answer 11

DNA base analogue
Activated by viral thymidine next kinase
Inhibits viral DNA synthesis

Question 12

What is aciclovir used to treat?

Answer 12

Herpes, meningitis, encephalitis

Question 13

What are the ADRs of aciclovir?

Answer 13

Nephrotoxicity
CNS symptoms (1-4%) e.g. tremor, myoclonus, hallucinations, coma

Question 14

At what stage in the infection is aciclovir effective?

Answer 14

In the acute phase when the patient is symptomatic

Question 15

What is ganciclovir used to treat?

Answer 15

CMV (retinitis & prophylaxis for transplant pts)

Question 16

What is the mechanism of action of ganciclovir?

Answer 16

Analogue of aciclovir
But activated by a different enzyme
Inhibits viral DNA synthesis

Question 17

What are the ADRs of ganciclovir?

Answer 17

Myelosuppressive
Carcinogenic/teratogenic
CNS symptoms (5-15%)

Question 18

What is cidofovir active against?

Answer 18

DS-DNA viruses:
Herpes
Pox
CMV

Question 19

What is the mechanism of action of cidofovir?

Answer 19

Inhibits DNA polymerase

Therefore, inhibits chain elongation

Question 20

ADRs of cidofovir?

Answer 20

Nephrotoxic
Myelosuppressive
Neutropenia (24%)

Question 21

What is foscarnet used for?

Answer 21

CMV when ganciclovir-resistant

HSV when aciclovir-resistant

Question 22

ADRs of foscarnet?

Answer 22

Narrow therapeutic index
Mainly nephrotoxic
CNS effects

Question 23

Name 2 NRTIs

Answer 23

Lamivudine

Zidovudine

Question 24

What is the mechanism of action of NRTIs?

Answer 24

Inhibit DNA polymerase & reverse transcriptase

Prevent viral replication

Question 25

ADRs of NRTIs?

Answer 25

Hyperlactataemia Lactic acidosis Hepatomegaly Steatosis (fat retention in cells)

Question 26

Name an NNRTI

Answer 26

Nevirapine

Question 27

What is the mechanism of action of NNRTIs?

Answer 27

Inhibits HIV reverse transcriptase | Used in combination with NRTIs (work at different sites)

Question 28

Give an example of a protease inhibitor?

Answer 28

Ritonavir

Question 29

What is a protease inhibitor used to treat?

Answer 29

HIV (in combo with 2 NRTIs)

Question 30

How do protease inhibitors work?

Answer 30

Block the cleavage of viral polyproteins by HIV protease enzyme Prevent production of viral proteins (no mature virions)

Question 31

ADRs of protease inhibitors?

Answer 31

Induction/inhibition of CYP450 (drug interactions) Chronic use - high cholesterol, TAG & glucose - increased risk of MI and diabetes

Question 32

Give an example of an integrate inhibitor

Answer 32

Raltegravir

Question 33

What are integrate inhibitors used for?

Answer 33

HIV in combo with 2 NRTIs

Question 34

What is the mechanism of action of integrate inhibitors?

Answer 34

Prevent integration of HIV DNA provirus into the host cell genome

Question 35

What is sofosbuvir used for?

Answer 35

Hep C

Question 36

What’s if the mechanism of action of sofosbuvir?

Answer 36

Blocks action of HCV viral polymerase | Prevents production of a new virus

Question 37

What is interferon alpha used to treat?

Answer 37

Hep B and C

Question 38

What is the mechanism of action of interferon alpha?

Answer 38

Immunomodulatory effect | Stimulates proteins to enhance resistance to viral infection

Question 39

What are the ADRs of interferon alpha? And when are they seen?

Answer 39

First few hours to days - flu-like illness, fever, chills, headache, myalgia, NV

Question 40

What is ribavirin used for?

Answer 40

Chronic hep C in combo with interferon alpha

Question 41

Mechanism of action of ribavirin?

Answer 41

Guanosine analogue Prevents viral mRNA capping Prevents assembly of viral genome Inhibits both RNA and DNA viruses

Question 42

ADRs of ribavirin?

Answer 42

Transient anaemia | Teratogenic

Question 43

What is adefovir used to treat?

Answer 43

Hep B

Question 44

What is the mechanism of action of adefovir?

Answer 44

False substrate and chain terminator of reverse transcriptase Inhibits HBV DNA polymerase as well

Question 45

What are the ADRs of adefovir?

Answer 45

Low doses - well-tolerated | High doses - nephrotoxicity