Antivirals

Question 1

Antigens on new viruses that are slightly mutated to prevent host immune system from recognizing the virus is called what?

Answer 1

Antigenic drift

*Larger changes that may result in viral epidemics are antigenic shifts

Question 2

Acyclovir, Valcyclovir, Famcyclovir, Penicyclovir, Ganciclovir and Foscarnet are antiviral drugs that act on what?

Answer 2

Inhibit DNA polymerase

Question 3

Amantadine is an antiviral drug that does what?

Answer 3

Inhibits viral uncoating (M2 Protein)

Question 4

Ribavarin is an antiviral drug that does what?

Answer 4

Inhibits viral translation by inhibit RNA polymerase

Question 5

Zanamivir and oseltamivir are antiviral drugs that do what?

Answer 5

Inhibit neuroaminidase (viral release)

Question 6

What are the two categories of Herpes simplex virus?

Answer 6

HSV Type 1 (Oral herpes, resides in trigeminal ganglia)

HSV Type 2 (Genital herpes, resides in sacral ganglia)

Question 7

What are the two main diseases caused by VZV?

Answer 7

1-Chickenpox (Varicella initial infection)

2-Shingles (herpes zoster reactivation)

Question 8

In general, canker sores are found ______ the mouth while Cold sores (fever blisters) are found _______ the mouth

Answer 8

Inside, outside

Question 9

What are the 3 main drugs used for Antiviral treatment of HSV and VZV?

Answer 9

1-Acyclovir (mainly HSV, 10x more potent against HSV than VZV)
2-Valacyclovir (converts to acyclovir via first pass metabolism)
3-Famiciclovir (metabolized to penciclovir, primarily used for VZV)

*Must hydrate well on these drugs to avoid crystalline nephropathy

Question 10

Which antiviral is used topically for orofacial or genital HSV related sores?

Answer 10

Penciclovir

Question 11

Which antiviral is approved for prophylaxis and treament of cytomegalovirus?

Answer 11

Gancyclovir

*contraindicated in pregnant or males who wish to bear children

Question 12

Which antiviral is used for CMV in immunocompromised patients and is useful when acyclovir or ganciclovir resistant?

Answer 12

Foscarnet

Question 13

What viral enzyme is necessary to activate acyclovir and allow it to incorporate into viral DNA, thus blocking its ability to elongate?

Answer 13

Viral Thymidine kinase

*acyclovir monophosphate lacks 3’ hydroxyl group and cannot be elongated

Question 14

What drug is 10x more potent against HSV 1 and 2 than against VZV?

Answer 14

Acyclovir

Question 15

What are the best drugs to treat varicella zoster virus from best to worst?

Answer 15

Famciclovir> Valacyclovir»»>acyclovir

Question 16

What drug is used when viral kinases have mutated to avoid cyclovirs and inhibits viral DNA polymerase enzymes?

Answer 16

Foscarnet

*IV only, nephrotoxicity

Question 17

What drug is used for prophylaxis and treatment of influenza A and B viruses?

Answer 17

Oseltamivir (Tamaiflu) neuroaminidase inhibitor

*early administration is crucial. Disulfuram like reaction

Question 18

Which drug is used for treatment and prophylaxis of influenza A and B and is administered in an inhalation route?

Answer 18

Zanamivir (Relenza)

*Disulfuram like reaction, contraindicated in severe asthma or those with Milk protein allergies

Question 19

Which drug is an antiviral and a weak anti-parkinsons drug and is effective against influenza A only?

Answer 19

Amantadine (blocks biral penetration/uncoating M2 Proteins)

*CNS side effects