Table 1.

Anti-influenza drugs.

Direct Acting Antiviral Drugs	Mechanism of Action of Antiviral Drugs	Side Effects
Oseltamivir (Tamiflu)	Competitive and selective inhibitor of neuraminidase of influenza viruses A and B	The gastrointestinal tract can be involved (nausea and vomiting; diarrhea, abdominal bloating, and fecal incontinence); central nervous system (dizziness, migraine, sleep disturbance, weakness); respiratory tract system (bronchitis, cough, infections of the upper respiratory tract); generalized pain
Zanamivir (Relenza)	Selective inhibitor of neuraminidase of influenza viruses A, inhibitor of replication and release of new virus particles	Allergies, breathing problems, dermatological disorders
Umifenovir (Arbidol)	A specific inhibitor of the fusion of a viral lipid membrane with cell membranes. Interacts with NA, prevents its conformation, which is necessary for the fusion of NA with endosome membranes. Interferon inductor. Stimulator of humoral and cellular immunity	Pruritus, rash, angioedema, urticaria, anaphylaxis
Riamylovir (Triazavirin)	Inhibitor of viral RNA synthesis and replication of genomic fragments	Allergies; the gastrointestinal tract can be involved (nausea and vomiting; diarrhea, abdominal bloating, and fecal incontinence)
Rimantadine, amantadine	M2 channel blockers. An inhibitor of the early stage of virus reproduction from the moment it enters the cell until the beginning of the transcription process. RNA inhibitor	The gastrointestinal tract can be involved (diarrhea); central nervous system (dizziness, migraine, sleep disturbance, weakness); respiratory tract system (cough); generalized pain; allergies