Antiviral drugs

Antiviral drugs - drugs that act on viruses by damaging their structures or disrupting vital functions.

Currently, a sufficient number of such drugs have been developed. All of them are classified according to the peculiarities of the pharmacological action and according to specific medical indications. The following groups of antiviral agents are distinguished: extended spectrum, antiherpetic, anti-cytomegalovirus, anti-influenza, anti-retroviral. The most famous representatives of the first type of medicines are Ribavirin and Lamivudine. These drugs have complex mechanisms of action associated with a decrease in nucleic acids through binding to viral enzymes. Based on the name, the scope of these drugs is quite wide and includes many DNA - and RNA-containing viruses that cause RS-syndrome, Las fever, hepatitis C, AIDS.

Antiherpetic drugs are represented by four drugs, which in their morphological composition are nucleoside analogues: acyclovir, penciclovir, famciclovir, valacyclovir. The last two dosage forms are inactive. In the human body, they turn into acyclovir and penciclovir. This determines their close morphological and histological properties.

The mechanism of action of acyclovir is to interact with the enzymes of the virus, after which their development cycle is interrupted. The result is the death of this microorganism. This interaction is ensured by the structure of acyclovir, which is an analogue of deoxyguanedine (purine nucleoside). The most sensitive to this drug is the herpes simplex virus. There are strains of microorganisms that are resistant to this drug. This effect can be explained by the use of immunosuppressive therapy. The mechanism of resistance is a mutation of the enzyme systems of the virus, a change in the specificity of the drug. In the event of such situations, drugs of other pharmacological groups are used (Foscarnet). Children's antiviral drugs include Valaciclovir. High bioavailability, which is more than fifty percent, causes a similar effect. This means that to achieve the effect, significantly lower doses of the drug are required (if compared with Acyclovir).

The mechanism of action of penciclovir is practically no different from the drugs of its group. It also disrupts the synthesis of the DNA microorganism. However, it differs in that it affects the Varicella-Zoster virus (VZV) to a greater extent.

Antimegalovirus drugs include Ganciclovir, Valganciclovir, Foscarnet, Tsidofovir, Fomiversen. They have a rather complex mechanism of action, which consists in competitive inhibition of the DNA polymerase of the microorganism. The result of this interaction is a violation of the extension of the DNA chain, which leads to its death. The best antiviral drugs that eliminate the symptoms of cytomegalovirus infection are the drugs of this pharmacological group. However, after prolonged use, drug resistance may develop, which somewhat reduces the spectrum of their use.

Antiviral drugs can have a direct effect on the human immunodeficiency virus. Therefore, the part of drugs that has a similar effect was combined into a group of antiretroviral drugs. All of them have a complex mechanism of action associated with the blocking of the enzyme systems of this microorganism, the violation of its replication.


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