Antiviral drugs are prescription medicines (pills, liquid, an inhaled powder, or an intravenous solution) that fight against viruses in the body. Key Points about antiviral drugs:

Able to enter the cells infected with virusAntiviral drugs.png
Interfere with viral nucleic acid synthesis and/or regulation
Some agent interfere with virus ability to bind with cell
Some agents stimulate the body's immune system
Mechanism of Action (in combination or single action)

Inhibit viral attachment
Prevent genetic copying of virus
Prevent viral protein production, vital for reproduction of virus.[1]
Diagram on R: Schematic description of the mechanism of the four classes of currently available antiviral drugs : fusion inhibitors (interfere with the binding, fusion or entry of a virion), reverse-transcriptase inhibitors (interfere with the translation of viral RNA into DNA), integrase inhibitors (block the viral enzyme integrase, that inserts the viral genome into the DNA of the host cell), protease inhibitors (block proteolytic cleavage of protein precursors that are necessary for the production of infectious viral particles)

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Virus Description
Viruses are obligate (ie by necessity) intracellular parasites.

They lack both a cell wall and a cell membrane
They do not carry out metabolic processes.
It must attach to and enter a host
It then uses the host cell's energy to synthesis protein, DNA and RNA
A virus is difficult to kill as it lives inside the hosts cell and a drug that kills the virus may also kill the cell[1].
Retroviruses are a type of virus in the viral family called Retroviridae. The antiviral drugs target diverse group of viruses such as herpes, hepatitis, and influenza viruses. Whereas antiretroviral are the drugs that are used to fight retrovirus infections which mainly include HIV. Different classes of antiretroviral drugs act on different stages of the HIV life cycle.[2].

There are many technical differences between viruses and retroviruses.

Generally, the main difference between the two is how they replicate within a host cell.
Retroviruses use RNA as their genetic material and are named for a special enzyme that’s a vital part of their life cycle — reverse transcriptase (Transcription is the process in cells by which an enzyme makes a copy of DNA from RNA. The enzyme that makes the DNA copy is called reverse transcriptase and is found in retroviruses).
The key steps that differentiate retroviruses from viruses are reverse transcription and genome integration[2].
Antiviral Drug Development
The emergence of antivirals is the product of a our newly acquired knowledge of the genetic and molecular function of organisms letting us better understand the structure and function of viruses, major advances in the techniques for finding new drugs, and the pressure placed on the medical profession to deal how to purchase remeron 15 mg with the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS).

First experimental antivirals were developed in the 1960s, mostly to deal with herpes viruses, and were found using traditional trial-and-error drug discovery methods.
Only in the 1980s, when the full genetic sequences of viruses began to be unraveled, did researchers begin to learn how viruses worked in detail, and exactly what chemicals were needed to thwart their reproductive cycle.[3]
Few drugs are selective enough to prevent viral replication without injury to the infected host cells.

Therapy for viral diseases is further complicated by the fact that the clinical symptoms appear late in the course of the disease, at a time when most of the virus particles have replicated.[4]

The 4 and 1/2 minute video below gives a good summary of Antiviral drugs


[5]

Virus Diseases
Viruses are composed of a single DNA or RNA inside a protein coat.
Viruses must enter a cell in order for them to carry on with their metabolic processes.
Upon successful entry, viruses inject their DNA or RNA to the cell and the cell is altered in such a manner that it is now “programmed” to control the metabolic processes that the virus needs to survive.
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Because viruses are contained in the cells, researchers find it difficult to develop antiviral drugs including vaccines.

Viruses that respond to antiviral therapy include

Influenza A viruses,
Herpes viruses,
Cytomegalovirus (CMV) Infection
HIV
Hepatitis B and C viruses
Some viruses that cause warts and eye infections.[6]
Antivirals - For Whom
Who should take antiviral drugs?

Most people will not require antivirals as they will have a mild illness and will recover quickly. In these cases the risk of side-effects from these drugs may outweigh the benefit of taking them.

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Candidates for antivirals are individuals who have:

Higher risk for complications from influenza
Adults 65 or older
Chronic diseases such as heart, lung, or kidney disease
Under age 4
Anyone with a compromised immune system.[7]
Note: how to purchase flagyl Important client aware of

Need for good (hand) hygiene when taking and proper application of ointments, aerosols powders
Not a cure cheap remeron 30mg but help to manage symptoms
Side Effects
Like all medicines, antivirals can cause side effects, although not everyone gets them.

Common side effects include:

nausea and vomiting
diarrhoea and stomach ache
headache
These side effects mostly occur after the first dose of the medicine and will usually stop as treatment continues.

Less common side effects include:

sleeping difficulties
skin reactions
heart rhythm abnormalities
hallucinations
abnormal behaviour[7]


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