Antivirals

Question 1

Atazanavir

Answer 1

Protease inhibitor

Question 2

Lopinavir

Answer 2

Protease inhibitor

Question 3

Darunavir

Answer 3

Protease inhibitor

Question 4

Fosamprenavir

Answer 4

Protease inhibitor

Question 5

Saquinavir

Answer 5

Protease inhibitor

Question 6

Ritonavir

Answer 6

Protease inhibitor

*Cytochrome P-450 inhibitor

Question 7

Tenofovir

Answer 7

Nucleotide Reverse Transcriptase Inhibitor

Question 8

Emitricitabine

Answer 8

Nucleoside Reverse Transcriptase Inhibitor

Question 9

Abacavir

Answer 9

Nucleoside Reverse Transcriptase Inhibitor

Question 10

Lamivudine

Answer 10

Nucleoside Reverse Transcriptase Inhibitor

Question 11

Zidovudine

Answer 11

Nucleoside Reverse Transcriptase Inhibitor

*Used for general prophylaxis & during pregnancy to reduce risk of fetal transmission

Additional SE: megaloblastic anemia

Question 12

Didanosine

Answer 12

Nucleoside Reverse Transcriptase Inhibitor

Question 13

Stavudine

Answer 13

Nucleoside Reverse Transcriptase Inhibitor

Question 14

Nevirapine

Answer 14

Non-nucleoside Reverse Transcriptase Inhibitor

Question 15

Efavirenz

Answer 15

Non-nucleoside Reverse Transcriptase Inhibitor

Teratogenic

Question 16

Delavirdine

Answer 16

Non-nucleoside Reverse Transcriptase Inhibitor

Question 16

Elvitegravir

Answer 16

Integrase Inhibitor

Inhibits HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase

SE: hypercholesterolemia

Question 17

Zanamivir

Answer 17

Inhibits influenza neuraminidase, decreasing the release of progeny virus

Tx: both influenza A and B

Question 18

Elvitegravir

Answer 18

Integrase Inhibitor

Question 19

Amantadine

Answer 19

Blocks viral penetration/ uncoating (M2 protein)

Prophylaxis and treatment for Influenza A; treats Parkinson’s

Toxicity: ataxia, dizziness, slurred speech

Mechanism of Resistance: mutated M2 protein

Rimantidine is a derivative w/ fewer CNS side effects (Doesn’t cross BBB)

Question 20

Oseltamivir

Answer 20

Inhibits influenza neuraminidase, decreasing the release of progeny virus

Tx: both influenza A and B

Question 22

Ribavirin

Answer 22

Inhibits synthesis of guanine nucleotides by competitively inhibiting IMP dehydrogenase

Tx: RSV, chronic hepatitis C

SE: Hemolytic anemia. Severe teratogen

Question 23

Acyclovir

Answer 23

Monophosphorylated by HSV/VZV thymidine kinase. Guanosine analog. Triphosphate formed by cellular enzymes. Preferentially inhibits viral DNA polymerase by chain termination.

Tx: HSV, VZV, EBV. No effect on latent HSV/VZV.

Valacyclovir (produg) has better oral bioavailability. For herpes zoster use famciclovir.

Mechanism of resistance: lack of viral thymidine kinase

Question 24

Ganciclovir

Answer 24

5’-monophosphate formed by a CMV viral kinase. Guanosine analog. Triphosphate formed by cellular kinases. Preferentially inhibits viral DNA polymerase.

Tx: CMV, especially in immunocompromised patients.

Valganciclovir (produg) has better oral bioavailability.

Toxicity: Leukopenia, neutropenia, thrombocytopenia, renal toxicity. More toxic to host enzymes than acyclovir.

Mechanism of resistance: Mutated CMV DNA polymerase OR lack of viral kinase

Question 25

Foscarnet

Answer 25

Viral DNA polymerase inhibitor that binds pyrophosphate-binding site of the enzyme. Does not require activation by viral kinase. Tx: CMV retinitis in immunocompromised pts when ganciclovir fails; acyclovir-resistant HSV Toxicity: Nephrotoxicity Mechanism of resistance: Mutated DNA polymerase

Question 26

Cidofovir

Answer 26

Preferentially inhibits viral DNA polymerase. Does NOT require phosphorylation by viral kinase. Tx: CMV retinitis in immunocompromised patients; acyclovir-resistant HSV. Long half life. Toxicity: Nephrotoxicity (coadminister w/ probenecid)

Question 27

Protease inhibitors

Answer 27

Prevent maturation of new viruses (HIV-1 protease cleaves polypeptide products of HIV mRNA into functional parts & allows assembly of virions) SE: hyperglycemia, GI intolerance, lipodystrophy

Question 28

NRTIs

Answer 28

Competitively inhibit nucleotide binding to reverse transcriptase and terminate the DNA chain (lack a 3'-OH group) *activated by thymidine kinase phosphorylation SE: bone marrow suppression, peripheral neuropathy

Question 29

NNRTIs

Answer 29

Bind to reverse transcriptase at a site different from NRTIs | *don't require phosphorylation for activation!

Question 30

Integrase Inhibitors

Answer 30

Inhibit HIV genome integration into host cell chromosome by reversibly inhibiting HIV integrase SE: hypercholesterolemia

Question 31

Enfuvirtide

Answer 31

Fusion inhibitor Selectively binds gp41 and prevents entry of HIV genome into unaffected CD4+ cells