Antiviral drugs Flashcards

1
Q

Acyclovir

A

Inhibits nucleic acid synthesis: competitive inhibitor of dGTP causing termination and trapping the DNA polymerase
Requires metabolic activation to triphosphate form (first one is by viral kinase)
Tx: herpes simplex virus 1 & 2, varicella zoster virus, cytomegalovirus
Poor oral bioavailability

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2
Q

Boceprevir

A

Prevents cleavage of precursor polypeptides of HCV: inhibits Ns3/4A serine protease

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3
Q

Foscarnet

A

Inhibition of pyrophosphate cleavage (need to cleave pyrophosphate before linking to the previous component and stops replication)
inhibits DNA/RNA pol and RT

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4
Q

Ganciclovir

A

Inhibits nucleic acid synthesis: competitive inhibitor of dGTP causing termination and trapping the DNA polymerase
Requires metabolic activation to triphosphate form (first one is by viral kinase)
Tx: herpes simplex virus 1 & 2, varicella zoster virus, cytomegalovirus
Poor oral bioavailability

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5
Q

Oseltamivir

A

Neuraminidase inhibitor: destroy receptors (sialic residues) recognized by viral hemagglutinin on cell surface
decrease in progeny virions
Viral aggregation at cell surface and reduced virus spread within respiratory tract
Prevents release of influenza A and B virus from infected cell

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6
Q

Ribavarin

A

Inhibits inosine monophosphate dehydorgenase
Inhibits nucleic acid synthesis: competitively inhibits GTP-dependent 5’ capping of viral mRNA and specifically influenza virus transcriptase activity
Multiple sites of interacting action of GTP-dependent enzymatic processes (some of these may potentiate others)
May enhance viral (lethal) mutagenesis
Converted to triphosphate

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7
Q

Trifluridine

A

Inhibits nucleic acid synthesis: irreversibly inhibits thymidylate synthase and specific DNA pol
Lesser extent: incorporated in cellular DNA in both infected and uninfected cells (decreasing host DNA synthesis)
Resistance is rare
Tx: HSV- induced keratitis and keratoconjunctivitis

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8
Q

Zanamivir

A

Neuraminidase inhibitor: destroy receptors (sialic residues) recognized by viral hemagglutinin on cell surface
decrease in progeny virions
Viral aggregation at cell surface and reduced virus spread within respiratory tract
Prevents release of influenza A and B virus from infected cell

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9
Q

Amantadine

A

Binds M2 protein: Ion channel blocker

Inhibits viral uncoating of Influenza A

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10
Q

Peginterferon Alfa

A

Inhibits protein synthesis directed by viral mRNA

Signals cell to make antiviral proteins: inhibit translation and other steps in viral replication

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11
Q

Rimantadine

A

Binds M2 protein: Ion channel blocker

Inhibits viral uncoating of Influenza A

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12
Q

Valacyclovir

A

Prodrug for acyclovir

Better oral bioavailability

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13
Q

Valganciclovir

A

Prodrug for ganciclovir

Better oral bioavailability

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14
Q

Abacavir

A

NRTI

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15
Q

Lamivudine

A

NRTI
Inhibits nucleic acid synthesis by HBV: competitively inhibits HBV DNA pol
Converted to triphosphate form

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16
Q

Tenofovir Disoproxil

A

NRTI

Already a monophosphate (nucleotide not a nucleoside)

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17
Q

Zidovudine

A

NRTI

decrease risk of fetal transmission

18
Q

Emtricitabine

A

NRTI

19
Q

Didanosine

A

NRTI

20
Q

Stavudine

A

NRTI

21
Q

Efavirenz

A

NNRTI

22
Q

Nevirapine

A

NNRTI

23
Q

Atazanavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus
NO CYP3A4 inhibition

24
Q

Ritonavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus
Inhibits CYP3A4

25
Q

Amprenavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus

26
Q

Indinavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus

27
Q

Lopinavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus

28
Q

Nelfinavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus

29
Q

Saquinavir

A

HIV-1 aspartyl protease inhibitor: inhibits cleavage of HIV gag and pol precursor polypeptides that include essential structural and enzymatic components of the virus

30
Q

Enfuvirtide

A

Fusion inhibitor (traps HIV and host at attachment stage): binds HR1, preventing HR2-HR1 interaction (binds gp41)

31
Q

Maraviroc

A

Fusion inhibitor: antagonist of CCR5 chemokine receptor that HIV uses for attachment and entry
Not all HIV strains use this receptor
CYP3A4 and P-gp

32
Q

Raltegravir

A

DNA strand transfer inhibitor

Inhibits integrase that integrates HIV DNA into host DNA

33
Q

Entecavir

A

Inhibits nucleic acid synthesis by HBV: competitive inhibitor of HBV DNA pol (dGTP)
Converted to triphosphate
Weak inhibitor of cellular DNA and mitochondrial polymerases

34
Q

Adefovir

A

Inhibits nucleic acid synthesis by HBV: competitive inhibitor of viral DNA polymerases and RT (dATP)
Converted to diphosphate form
Higher affinity for HBV than host

35
Q

Telbivudine

A

Inhibits nucleic acid synthesis by HBV: competitive inhibitor of HBV DNA pol (Thymidine 5”-triphosphate)
Converted to triphosphate form
Little toxicity toward human DNA pol

36
Q

Telaprevir

A

Inhibits cleavage of precursor polypeptides of HCV: inhibits Ns3/4A serine protease

37
Q

NRTI

A

Nucleoside Reverse Transcriptase Inhibitors: competitive inhibition (bind active site) by competing with endogenous nucleosides for incorporation into viral DNA (indirectly inhibits pol); terminate DNA (lack 3’ OH)
Also inhibit host cell mitochondrial DNA pol: Many significant toxicities (anemia, granulocytopenia, myopathy, peripheral neuropathy, and pancreatitis)
Converted to triphosphate nucleotides by host cell kinases
Resistance: thymidine analog mutations (TAMS); change of target and host repair systems
NO CYP interactions

38
Q

NNRTI

A

Non-Nucleoside Reverse Transcriptase Inhibitors: bind to hydrophobic pocket of the p66 subunit of HIV-1 RT; non competitive inhibitors (change dynamic of receptors)
Resistance: mutation in p66 pocket without affecting enzyme activity of virus
Specificity for HIV-1
ALL CYP substrates (all but one inducers or inhibitors)
Do NOT require phosphorylation

39
Q

Protease inhibitor issue

A

Protease: Clip precursor into individual proteins
Primary mutation: doesn’t necessarily make resistance
Secondary mutation: need multiple mutations to evade drug
substrates for P-gp energy dependent efflux pump
ALL substrates and inhibitors of CYP3A4

40
Q

HAART therapy

A

Start at time of HIV dx

2 NRTI + 1 NNRTI or protease inhibitor or integrase inhibitor