Antiviral agents and resistance

Question 1

Zidovudine

Answer 1

NRTI for HIV

Question 2

Non-nucleoside RT inhibitors (NNRTI)

Answer 2

Allosteric inhibition of RT, inactive against HIV 2 in west Africa

Question 3

Penciclovir/Famiclover

Answer 3

Progdrug is famiciclovir, used to treat shingles

Question 4

AZT/Azidothymidine

Answer 4

NRTI for HIV, mimics deoxythymidine, RT of HIV is 100x more sensitive to AZT than other cellular polymerases.

Question 5

Nevirapine

Answer 5

NNRTI for HIV

Question 6

Efavirenz

Answer 6

NNRTI for HIV

Question 7

Aciclovir/Cyclovir

Answer 7

Competitive inhibitor of DNA polymerase, selective toxicity due to unique viral kinase to phosphorylate nucleosides, resistance from mutated viral thymidine kinase or DNA polymerase,

topical, oral, iV for HSV-1,2, and VZV, .

Aciclovir resembles Guanine

Question 8

Ritonavir

Answer 8

Protease Inhibitor for HIV

Question 9

Enfuvirtide

Answer 9

blocks membrane fusion of HIV to virus membrane.

Question 10

Ganciclovir and Valganciclovor

Answer 10

Against cytomegalovirus (HSV), not as selective, suppressive of bone marrow, resisted by DNA polymerase or kinase. Progdrug is Valganciclovor

Question 11

Chemokine receptor Antagonists and fusion inhibitors

Answer 11

May use CCR5 or CXCR4 as coreceptor which can be blocked for HIV. Fusion inhibitors prevent viral entry by membrane fusion. Genotypeing helps predict coreceptor use of HIV

Question 12

Valaciclovir

Answer 12

Prodrug for aciclovir, esterfied with valine as an oral drug for HSV-1

Question 13

Protease Inhibitors

Answer 13

HIV produces polyproteins which are cleaved by a protease, protease inhibitors are very potent, competitive inhibition

Question 14

Integrase strand transfer inhibitor

Answer 14

inhibit step 3 in proviral integration (HIV): inhibits the ligation fo DNA molecules via phophodiester bonds between the terminal nucleotide of the viral genome 3’ ends and 5’ ends.

Question 15

Maravicc and Vicriviroc

Answer 15

Block coreceptor CCR5 binding of HIV

Question 16

Lopinavir

Answer 16

Protease inhibitor for HIV

Question 17

Ibalizumab

Answer 17

affects CD4 binding of HIV to gp120

Question 18

Nucleosides/nucleotide reverse transcriptase inhibitors (NRTI)

Answer 18

Azidothymidine mimics deoxythymidine, competitive inhibitor of dna polymerases for HIV. Prevents extension of growing DNA chain due to lack of 3’-OH.