[Synergic therapeutic action of aprotinin and remantadine in experimental influenzal infection].

Chemotherapeutic treatment of influenza infection is possible with aprotinine, an inhibitor of proteinases blocking proteolytic shearing of virion hemagglutinin which is necessary for multicycle virus infection. The chemotherapeutic effect of antiinfluenza drug remantadine is due to inhibition of intracellular deproteinization of virions in the course of their penetration into cells. In mice infected with a highly lethal dose (about 400 MLD50/animal) of influenza A/Aichi/2/68 (H3N2) virus treatment with remantadine protected from death 12% of the animals, aprotinine 36%, and combined treatment with aprotinine and remantadine induced protection in 72%. The mice receiving combined treatment showed minimal pathological lesions in the lungs whereas control untreated animals had total hemorrhagic pneumonia. Thus, combined use of drugs blocking different stages of virus reproduction may have a synergetic therapeutic effect inducing a potentiating protective effect in the animals inoculated with a high dose of influenza virus.