Antibiotics VI (Antivirals)

Question 1

What are the agents used to treat DNA viruses and their respective viruses?

Answer 1

• Nucleoside analogs for HSV/VSV (acyclovir)
• Nucleoside analogs for CMV (ganciclovir)
• Pyrophosphate analog for HSV/VSV/CMV (Foscarnet)

Question 2

What are the generalizable MOA of the antivirals for DNA viruses?

Answer 2

• Typically prodrug
• Require bioactivation
• Active cogener binds to the nucleic acid polymerase
• Cogener lacks essential functional group to continue replication
• Termination of nucleic acid synthesis

Question 3

What is a vital characteristic that applies to all antivirals?

Answer 3

The must have a greater affinity for viral activating enzyme than the mammalian counterpart

Question 4

What is acyclovir active against?

Answer 4

HSV and VZV

Question 5

What is ganciclovir effective against?

Answer 5

CMV in HIV patients

Question 6

Which disease requires a higher dose of acyclovir? HSV or VZV?

Answer 6

VZV

Question 7

Why is acyclovir so widely used? What are its SEs?

Answer 7

Relatively well-tolerated

CNS side effects (seizures, altered mental status) can occur if IV acyclovir is dosed inappropriately

Question 8

What is the structure that ganciclovir mimics?

Answer 8

guanine analogue specifically for CMV

Question 9

What is the main utility of ganciclovir?

Answer 9

Tx and prophylaxis of CMV retinitis in HIV

Question 10

SEs of ganciclovir?

Answer 10

• Neutropenia and Thrombocytopenia are major dose-dependent (and dose-limiting) toxicities
• Adverse CNS effects

Question 11

Serious complication of CMV in HIV patients?

Answer 11

CMV retinitis

Question 12

What is the broad spectrum antiviral drug?

Answer 12

Foscarnet (pyrophosphate congener)

Question 13

What is the spectrum of foscarnet?

Answer 13

HSV/VZV/CMV and RNA viruses including HIV

Question 14

When would Foscarnet be used instead of acyclovir?

Answer 14

If acyclovir resistant-HSV/VZV strains are infectious agent

Question 15

What are the most commonly used neuraminidase inhibitors?

Answer 15

Oseltamivir

Question 16

What is oseltamivir used to treat?

Answer 16

Influenza A and B

Question 17

How do neuraminidase inhibitors work?

Answer 17

Prevent viral release from host cells

Question 18

When is prophylactic oseltamivir use considered?

Answer 18

Seasonal prevention for high risk populations (Nursing home patients), Post-exposure prophylaxis for family members at high risk for severe disease

Question 19

What is the optimal treatment window for oseltamivir?

Answer 19

Within 1-2 days of Syx onset

Question 20

SEs of oseltamivir?

Answer 20

Neuropsyciatric toxicity - when overprescribed

Question 21

What are the nucleoside reverse transcriptase inhibitors for HIV?

Answer 21

Zidovudine (Retrovir) and Lamivudine

Question 22

What is the non-nucleoside reverse transcriptase inhibitor used for HIV?

Answer 22

efavirenz

Question 23

What are the HIV protease inhibitors?

Answer 23

Amprenavir, ritonavir

Question 24

What are the protease inhibitors for HCV?

Answer 24

Bocepravir, telepravir

Question 25

What two drugs are used for resistant strains of HIV?

Answer 25

• Fusion inhibitor - enfurvitide
• Integrase inhibitor - raltegravir

Question 26

What are the side effects of protease inhibitor drugs?

Answer 26

Lipodystrophy syndrome: Major long term adverse effects from class are hyperglycemia, hyperlipidemia, and fat distribution

Question 27

What is the general strategy for HIV Tx?

Answer 27

Combination Tx with many drugs

Question 28

What is the most aggressive schema in HAART?

Answer 28

Two NRTIs, a NNRTI, and a protease inhibitor