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28 Cards in this Set
- Front
- Back
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Which antivirals can be used against active, replicated HSV, VZV and EBV? |
Acyclovir, penciclovir, famcyclovir and valacyclovir |
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Which antiviral can be used for treatment or prophylaxis for CMV infections in AIDS and organ transplant patients? |
Ganciclovir and valganciclovir (prodrug) |
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Which antiviral is used against ganciclovir- and acyclovir-resistant infections? |
Foscarnet |
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Which antiviral is used to treat CMV retinitis? |
Cidofovir |
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Mechanism of action of acyclovir and penciclovir? |
They are inactive guanosine analogues that get activated by virally encoded thymidine kinase. They inhibit DNA polymerase and chain termination. Activation by virally encoded enzymes makes them specific for infected cells. |
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Mechanism of action of ganciclovir? |
It is an inactive guanosine analogue that gets activated by UL97 kinase. The active form will competitively inhibit DNA polymerase and chain termination. It is not so specific for infected cells. |
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Mechanism of action of Foscarnet? |
It is a pyrophosphate analogue. It directly inhibits viral DNA polymerase by binding to its pyrophosphate binding site. No activation is needed. |
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Mechanism of action of Cidofovir? |
It is a cytidine analogue. It get activated intracellularly and competitively inhibits viral DNA polymerase. |
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How can resistance against acyclovir, penciclovir and ganciclovir occur? |
Mutations in thymidine kinase or UL97 kinase (ganciclovir) |
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How can resistance against forscarnet and cidofovir appear? |
Mutations in viral DNA polymerase. |
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How is the dosing of acyclovir vs valacyclovir? |
Acyclovir has poor oral bioavailability and short half-life. It has to be given often, 800 mg 5 times a day. Valacyclovir has good oral bioavailability, and 1000 mg is given 3 times a day. |
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Which antivirals against herpes can only be used topically? |
Penciclovir and ganciclovir |
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Which antivirals against herpes can only be given IV? |
Forscarnet and cidovir |
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Adverse effects of acyclovir? How to prevent this? |
Acute kidney injury when given IV because acyclovir crystallize in the kidneys. Important with enough hydration. |
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Adverse effects of foscarnet? |
Nephrotoxic, GI toxic, CNS toxic and anemia. Side effects are common |
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Adverse effects of ganciclovir? |
Pancytopenia, especially if together with NRTIs like zidovudine. CNS toxicity. |
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Name antivirals against hepatitis B? |
Interferon-a, pegylated interferon-a, tenofovir, lamivudine, entecavir |
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What are the first-line choices when treating hepatitis B? |
Entecavir and tenofovir |
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Mechanism of action of interferon-a? |
Inhibits viral protein synthesis, promotes breakdown of viral RNA and induces expression of MHC I molecules on infected cells, so CD8+ positive T-cells can kill them. |
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Mechanism of action of tenofovir? |
It is a nucleotide analogue which binds to viral DNA polymerase and interfere with DNA transcription. |
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Mechanism of entecavir and lamivudine? |
Nucleoside analogues that inhibit the enzyme reverse transcriptase. |
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Adverse effects of interferon-a? |
- Flu-like symptoms - Suppresses bone marrow and CNS - Induce production of antibodies which can lead to an autoimmune disease or worsening of one. |
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Adverse effects of tenofovir? |
Rare. - Dose-dependent nephrotoxicity - Exacerbation of hepatitis during treatment and discontinuation. |
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Name antivirals against hepatitis C |
- (pegylated) interferon, Ribavirin - Protease inhibitors: Simeprevir - NS5B RNA polymerase inhibitors: Sofusbuvir - NS5A replication complex inhibitors: Velpatasvir |
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What do we give for acute hepatitis C to cure it? |
Pegylated interferon-a for 6 months |
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What do we give to treat chronic hepatitis C? |
It depends on the genotype of the HCV, but the best regimens are one NS5B inhibitor and one NS5A inhibitor |
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Mechanism of ribavirin? |
It is a guanosine analogue which prevents synthesis of guanine nucleoside. |
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Adverse effects of ribavirin? |
- Hemolytic anemia in 1of 3 patients. - Nausea and cough |
