Effect/Active substance groups
Antiviral agents can be differentiated according to their mode of action. They hinder the reproduction of viruses in different stages. To prevent this mechanism, one must first consider the stages that are passed through during virus replication.
First, the viruses bind to the surface of the host cell (human cells). When the virus docks, a protein molecule on the surface of the virus binds to a specific receptor of the host (absorption). Depending on the type of virus, the virus then enters the cell, either by fusion between the virus envelope and the cell membrane or by infiltration through newly formed pores in the membrane of the host cell.Once the virus has entered the host cell, it releases its genetic information (genome).
This process is called “uncoating”. The viral genome is then replicated in several intermediate steps. Finally, the virus particles are assembled (maturation) and the finished viruses are released.
Drugs can be applied at all these junctions and prevent the virus from multiplying. This results in the following groups of active ingredients: Firstly, entry inhibitors, because they prevent the virus particles from docking to the cell membrane of the host (Ancriviroc, Aplaviroc). Then penetration inhibitors, which serve to prevent the virus particles from entering the host cell and thus also prevent “uncoating” (amantadine, pleconaril).
This is followed by the huge group of inhibitors of multiplication. These include several subgroups that prevent the synthesis of nucleic acids or proteins. They include This subdivision, however, is quite confusing and difficult to understand.
They are suitable in their effectiveness against the enzymes which are needed for replication. Other inhibitors that prevent the composition of the viruses are also important, such as the drug Bevirimat against HIV. Finally, there are neuraminidase inhibitors which prevent the release of the newly produced viruses.
Examples of these are oseltamivir and zanamivir, drugs against the influenza viruses.
- DNA polymerase inhibitors
- DNA/RNA polymerase inhibitors
- RNA polymerase inhibitors
- Reverse transcriptase inhibitors
- Inosine monophosphate dehydrogenase inhibitor
- Protease inhibitors
- Integrase inhibitors
- Antisense oligonucleotides
- Helicase Primase Inhibitors
The spectrum of side effects of this group of drugs is as large as the number of different active ingredients and, in addition to the type of application, also depends on the administered dose. In general it can be said that the locally and externally applied substances are well tolerated and the side effects are limited to the area of application.
The orally or intravenously administered substances have effects on the whole body and usually trigger nausea, headaches or diarrhoea. In particular, active ingredients that are effective against several pathogens more frequently trigger side effects. Active ingredients that are metabolised and broken down by the liver are problematic, as they can become even more harmful to patients with liver damage. The specific side effects of the individual active ingredients can be read in the package inserts.
