Lixin Liu Flashcards
Virus Particle (Virion) Components
- Envelope
- Core proteins (capsid)
- RNA or DNA core (nucleois)
- Surface proteins
Where do RNA viruses form their mRNA?
Cytoplasm except for influenza viruses
RNA retroviruses contain which type of DNA?
cDNA which are pro viruses that can be transcribed into new viral genomic RNA and mRNA
DNA viruses enter where?
Enter the nucleus to form viral mRNA
Viruses assemble these is the host cell
Virions which are released during cell lysis or budding (enveloped viruses)
DNA viruses blocking site?
Inhibition of viral DNA polymerase
RNA viruses blocking sites?
Block the uncoating, RNA polymerase, or the release of the virus
Neuraminidase inhibitors
Remove sialis acid receptors from viral particles and from cell surface, preventing self-aggregation and gluing to infected cell surface
Oseltamivir
- oral
- active prodrug
- hydrolyses in the liver to active components
- used for influenza A and B
Oseltamivir side effects
GI discomfort and nausea
Zanamivir
- inhaled or intranasally or intravenous
- contraindicated in patients with severe respiratory diseases or asthma
- Influenza A and B use
Peramivir
- intravenous only
- influenza A and B use
Peramivir adverse effects
Serious skin reactions
Amantadine and rimantadine action
- blocks viral membrane matrix protein M2
- viral uncoating inhibitors
- Amantadine is effective in treating some Parkinson’s disease
Administration of Amantadine and Rimantadine
Orally for Influenza A only
Ribavirin used to treat
- severe RSV in children
- treatment of influenza
- chronic hepatitis C infections
Ribavirin action
Inhibits GTP formation, viral mRNA capping, and thereby inhibits viral protein synthesis
Ribavirin routes of administration
- oral
- IV
- aerosol
Interferon mode of action (3)
- induction of host cell enzymes that inhibit viral RNA translation
- degradation of viral RNA
- stimulation of immune system
- for treatment against hepatic viral infections
Interferon route of administration
Intralesionally, subcutaneously, or intravenously
Interferon adverse effects
Flu-like symptoms, bone marrow suppression, neurotoxicity, autoimmune disorders
Lamivudine mode of action
Inhibits both HBV DNA polymerase and HIV reverse transcriptase
- for treatment of HBV and HIV
Lamivudine route of administration
Orally
Acyclovir treatment of
- drug of choice for HSV types 1 and 2 as well as VZV
Acyclovir route of administration
IV, oral, and topical
Acyclovir mode of action
- competitive inhibition of dGTP for viral DNA polymerase
- binding to DNA template, causing termination of premature viral DNA
- trapping the viralDNA polymerase on acyclovir-terminated DNA chain
Adverse effects of Acyclovir
Depends on the route of administration
- Topical: local irritation
- Oral: headache and GI upsets
- IV: transient renal dysfunction at high dose
Nucleoside and Nucleotide Reverse Transcriptase Inhibitors (NRTI’s)
- pro drugs
- convert to the triphosphates in the cell
- incorporated by viral reverse transcriptase into viral DNA to terminate its elongation
- Have much lower affinity to host cell DNA polymerase but affect mitochondria DNA polymerase in certain tissues
Zidovudine
Converted by mammalian thymidine kinase to triphosphate introduced by viral reverse transcriptase into viral DNA
- Used in HAART, decreases viral load and increases CD4+ cells. Also used for prophylaxis
Zidovudine route of administration
Orally administered, glucuronylated by the liver