Human experience from the field of chemotherapy for viral infections shows that a specific antiviral drug used in medical practice, taking into account international recognition, certainly must meet three fundamental requirements:
The first is that the antiviral drug should act only at a certain stage of the reproduction of the virus, this effect should be strictly selective. Damage to one or another stage of virus reproduction should not affect the life of the cells, organs, and the host organism.
Antiviral drugs theoretically should not have side effects, for example, the primary damage to the synthesis of viral nucleic acids should be strictly selective and not be accompanied by inhibition of the synthesis of the actual cellular nucleic acids. The safety and tolerability of drugs is determined by this property of an antiviral substance.
The second is an anti-virus compound (i.e. drugs) with such unique properties that should have optimal bioavailability, pharmacokinetic properties during its use for medical purposes. Its concentration in the blood, in cellular systems and organs affected by a viral infection, should significantly exceed that concentration of the drug that provides a pronounced antiviral effect in vitro experiments, and such a concentration should be maintained constantly in the patient’s body during the entire course of the use of antiviral drugs.
The optimal concentration of the antiviral drug is crucial to prevent the development of drug resistance due to the formation of a mutant viral population resistant to the study drug. Therefore, it is important in the process of both preclinical and clinical studies of the antiviral drug to form the optimal scheme for its use.
Third, the creation of an antiviral drug depends entirely on the objectivity of methods for evaluating the antiviral effect, through the achievements of molecular virology and the unlimited possibilities of modern chemical science. This is the basis for the formation of a systematic approach for the production of modern anti-virus drugs.