Non-HIV Antivirals

Question 1

1st line drug for HSV

Answer 1

Acyclovir

Question 2

Mechanism of Acyclovir

Answer 2

Nucleoside analog - requires phosphorylation before it gets incorporated into the genome. Only viral thymidine kinase phosphorylates it.

Question 3

Acyclovir ADME

Answer 3

PO (low bioavailability), IV, topical. Diffuses into most tissues, including CSF. Hepatic metabolism, renal excretion.

Question 4

Acyclovir toxicities

Answer 4

Nausea, diarrhea, HA, IV - renal toxicity, neurotoxicity.

Question 5

Anti Cytomegalovirus Drugs

Answer 5

Ganciclovir Foscarnet

Question 6

Ganciclovir mechanism

Answer 6

Guanosine Analog - phosphorlyated to active form by CMV kinase

Question 7

Who needs CMV prophylaxis

Answer 7

Immunosuppressed - post transplant or HIV.

Question 8

Foscarnet mechanism

Answer 8

Inhibits viral DNA and RNA polymerase. No activation required.

Question 9

Foscarnet ADME

Answer 9

IV only, CSF - 60% of plasma concentration. Renal clearance.

Question 10

Foscarnet Toxicities

Answer 10

Renal toxicity, electrolyte imbalances.

Question 11

Interferon mechanism (general)

Answer 11

Cytokines - bind to receptor - induces intracellular signals inhibiting viral life cycle. Increases MHC antigens and action of phagocytes and T cells.

Question 12

Interferon toxicity

Answer 12

Flu like symptoms, LFT elevation, abortion (CI in pregnancy)

Question 13

Ribivarin mechanism

Answer 13

Guanosine analog - phosphorylated by HOST CELL. Blocks capping of viral mRNA, inhibits viral R poly.

Question 14

Ribavarin ADME

Answer 14

Inhaled, high concentration in respiratory tract and RBC’s, Hepatic metabolism, renal excretion.

Question 15

Ribavarin toxicity

Answer 15

Hemolytic anemia/. teratogenic, mutogenic in animals.

Question 16

Drugs for HCV

Answer 16

Sofosbuvir - most effective.
Ledipsavir/Sofosbuvir
Ribavarin, Simeprevir

Question 17

Simeprevir mechanism

Answer 17

Protease inhibitor - NS3/4A protease

Question 18

Simeprevir toxicity

Answer 18

Rash, photosensitivity, elevated bilirubin/uric acid. Drug drug interactions due to CYP3A4 inhibition - especially with statins

Question 19

Sofosbuvir mechanism

Answer 19

RNA dependent RNA polymerase inhibitor.

Question 20

Sofosbuvir toxicity

Answer 20

CI with p-glycoprotein inducers (rifampin), CI with shitty insurance ($1000 a pill)

Question 21

Ledipsavir/Sofosbuvir mechanism

Answer 21

Inhibits NS5A protein - inhibits viral replication.

Question 22

Ledipsavir/Sofosbuvir toxicity

Answer 22

well tolerated, but $1,125 per pill

Question 23

Anti Influenza Drugs

Answer 23

Amantidine Oseltamivir, Zanamivir

Question 24

Oseltamivir, Zanamivir mechanism

Answer 24

Neuraminidase inhibitors - inhibit release of progeny viruses.

Question 25

Oseltamivir ADME

Answer 25

PO, protein bound, HEPATIC ACTIVATION, renal excretion

Question 26

Amantadine mechanism

Answer 26

Inhibits uncoating of viral RNA. Resistance is common, not used.