How do antiviral medications inhibit viral replication?
An antiviral agent must act at one of five basic steps in the viral replication cycle in order to inhibit the virus: (1) attachment and penetration of the virus into the host cell, (2) uncoating of virus (e.g., removal of the protein surface and release of the viral DNA or RNA), (3) synthesis of new viral components by …
How does acyclovir stop viral replication?
Acyclovir triphosphate prevents viral DNA synthesis by inhibiting the viral DNA polymerase. In vitro, acyclovir triphosphate competes with deoxyguanosine triphosphate as a substrate for viral DNA polymerase.
What are antiviral agents explain in detail about the structure and mechanism of action two antiviral agents?
An analysis of the action mechanism of known antiviral drugs concluded that they can increase the cell’s resistance to a virus (interferons), suppress the virus adsorption in the cell or its diffusion into the cell and its deproteinisation process in the cell (amantadine) along with antimetabolites that causes the …
How Do antivirals work microbiology?
Most of the antiviral agents work by inhibiting viral DNA synthesis. These drugs chemically resemble normal DNA nucleosides, molecules containing deoxyribose and either adenine, guanine, cytosine, or thymine. Viral enzymes then add phosphate groups to these nucleoside analogs to form DNA nucleotide analogs.
What are three modes of action for antiviral drugs?
The possible modes of action of anti-viral agents would include being able to …
- Inactivate extracellular virus particles.
- Prevent viral attachment and/or entry.
- Prevent replication of the viral genome.
- Prevent synthesis of specific viral protein(s).
- Prevent assembly or release of new infectious virions.
Why acyclovir is less toxic to normal human cells?
Activation of acyclovir to form the nucleoside triphosphate is dependent upon a promiscuous viral thymidine kinase; the low toxicity of acyclovir is due to the activation of acyclovir only in infected cells and the low inhibition of cellular replication (19).
How does acyclovir cause chain termination?
Acyclovir triphosphate inhibits viral DNA synthesis by competing with deoxyguanosine triphosphate (dGTP) as a substrate for viral DNA polymerase, as illustrated in Figure 1. Since acyclovir triphosphate lacks the 3′-hydroxyl group required for DNA chain elongation, the growing chain of DNA is terminated.
What is the pathophysiology of antivirals?
Antivirals can: Block receptors so viruses can’t bind to and enter healthy cells. Boost the immune system, helping it fight off a viral infection. Lower the viral load (amount of active virus) in the body.
Which is a mechanism of action of an antiviral?
The mechanism of antiviral activity consists of its transformation to triphosphate and subsequent inhibition of viral DNA synthesis.
What is the basic structure of a virus?
Viruses are much smaller than bacteria and consist of a single- or double-stranded nucleic acid (DNA or RNA) surrounded by a protein shell called a capsid; some viruses also have an outer envelope composed of lipids and proteins. They vary in shape. The two main classes are RNA viruses and DNA viruses.
What is the chemical structure of acyclovir?