Antiviral_part2_Flashcards
What patients are primarily affected by Cytomegalovirus (CMV) infections?
Advanced immunosuppressed patients.
What are the causes of CMV infections?
Retinitis, colitis, esophagitis, CNS disease, and pneumonia.
List the drugs used for CMV infections.
- Ganciclovir
- Valganciclovir (a prodrug of ganciclovir)
- Cidofovir
- Foscarnet
What types of infections are caused by Herpes viruses (HSV)?
- Herpes simplex virus (HSV) infections
- Varicella-zoster virus (VZV) infections
Name the systemic drugs for HSV infections.
- Acyclovir (oral, IV administration)
- Valacyclovir (oral, prodrug of acyclovir)
- Famciclovir (oral, prodrug of penciclovir)
- Foscarnet (IV)
Name the topical drugs for HSV infections.
- Acyclovir
- Trifluridine
- Penciclovir
- Docosanol
What are the clinical effects of systemic HSV drugs?
- Decrease the duration of symptoms.
- Decrease the time to lesion healing.
- Decrease the duration of viral shedding.
In what scenario are HSV drugs given prophylactically?
To prevent HSV disease in bone marrow transplant recipients.
Do systemic HSV drugs act on latent viruses?
No, they do not act on latent viruses.
What is the mechanism of action (MOA) for nucleoside analogs in HSV treatment?
- Require viral enzyme-mediated phosphorylation.
- Inhibit viral DNA polymerase by mimicking nucleosides.
Name the nucleoside analogs used for HSV infections.
- Acyclovir
- Penciclovir
- Ganciclovir
- Trifluridine
What is the difference between nucleoside and nucleotide analogs?
- Nucleoside analogs: Require phosphorylation.
- Nucleotide analogs: Already contain one phosphate group.
Give an example of a nucleotide analog and its specific characteristic.
Cidofovir; contains a nitrogen and two phosphates.
Which HSV drug is specifically noted for IV administration and targets drug-resistant viruses?
Foscarnet.
What is the specific role of Valacyclovir and Famciclovir in HSV treatment?
- Valacyclovir: A prodrug of acyclovir.
- Famciclovir: A prodrug of penciclovir.
What is required for activation of nucleoside analogs in cells?
2 or 3 phosphorylation steps.
What is the mechanism of action of nucleoside analogs?
- Inhibit viral DNA polymerase.
- Permit limited viral DNA elongation or cause premature DNA chain termination.
What is Foscarnet classified as?
A non-nucleoside/nucleotide analog.
What is the chemical nature of Foscarnet?
Inorganic pyrophosphate analog.
Does Foscarnet require phosphorylation for activation?
No, it does not require phosphorylation.
What is the mechanism of action of Foscarnet?
Inhibits viral DNA polymerase.
What is Docosanol and its mechanism of action?
Type: Alcohol.
Action: Inhibits fusion between the HSV envelope and the host cell membrane.
List the common side effects of oral Acyclovir and Valacyclovir.
Nausea, diarrhea, and headache.
What are the side effects of intravenous Acyclovir infusion?
- Reversible renal toxicity.
- Neurologic effects.
What is the major side effect of Ganciclovir and Valganciclovir?
Myelosuppression.
What is the key side effect of Cidofovir and Foscarnet?
Nephrotoxicity.
Which antiviral drugs do not require phosphorylation for activation?
Foscarnet.
How does Docosanol differ in its action compared to nucleoside analogs?
It inhibits membrane fusion, not viral DNA polymerase.
What is a common mechanism among drugs like Acyclovir and its analogs?
Inhibition of viral DNA polymerase.
Why might Foscarnet be used over nucleoside analogs?
It bypasses the need for phosphorylation, making it effective against drug-resistant viruses.
