Antivirals(Fixed)

Question 1

What is the general mechanism of action for antivirals?

Answer 1

–>inactive prodrugs that have a much higher affinity for viral activating enzyme (as opposed to mammalian) –>Binding to enzymes produce inactive compounds, which stop nucleic acid synthesis

Question 2

What are 3 antivirals that are used for DNA viruses? Which of these is not like the other?

Answer 2

Acyclovir - nucleoside analog (chain terminator)Ganciclovir - nucleoside analog (chain terminator)Foscarnet - pyrophosphate congener; highly ionized and cannot be given orally; broad spectrum- also works against RNA viruses

Question 3

What are the uses and adverse effects of acyclovir, gancliclovir and foscarnet?

Answer 3

-Acyclovir: HSV, VZV (requires higher dose)–>well tolerated; CNS side effects if improper dosage in context of renal failure -Ganclicovir: CMV retinitis in HIV–> CNS effects; dose-dependent hematotoxicity (leukopenia, thrombocytopenia)-Foscarnet: broad spectrum (DNA & RNA viruses); resistant HSV/VZV, CMV–>dose-dependent renal and CNS toxicities

Question 4

What agent is used for prophlyaxis or to shorten duration of influenza A and B? mechanism? Toxicity?

Answer 4

Oseltamivir (Tamiflu)–>inhibits neuraminidase to prevent viral release from host cells-SE: neuropsychiatric toxicity

Question 5

What are the 3 classes of agents used in HAART therapy? Mechanism of each?

Answer 5

2 NRTIs (w/diff side effect profiles)NNRTI[both inhibit reverse transcriptase but at diff sites]Protease Inhibitor (prevents chopping up of protein chain into functional subunits)

Question 6

What are the 2 NRTIs used in HAART therapy? Which one may also be used in the treatment of Hepatitis B?

Answer 6

ZidovudineLamivudine (also HBV treatment)

Question 7

Which HAART therapy drug class has a high rate of skin rashes? Name an agent of that class.

Answer 7

NNRTIs- Efavirenz

Question 8

Name 4 Protease Inhibitors. Which are used for HIV and which for HCV? Adverse effect?

Answer 8

HIV: amprenavir & ritonavirHCV: boceprevir & teleprevir–> Lipodystrophy syndrome (hyperglycemia, hyperlipidemia, fat distribution)

Question 9

What is Raltegravir?

Answer 9

HIV integrase inhibitor–> binds to HIV integrase to prevent viral DNA strand transfer

Question 10

What class are Enfurvitide and Maraviroc? Mechanism?

Answer 10

Fusion inhibitors–>prevent viral cell entry by steric hindrance of gp41 (enfuvirtide) and CCR5 (maraviroc)