Therapeutic effects of ribavirin given by the intraperitoneal or aerosol route against influenza virus infections in mice.

Ribavirin (1-beta-d-ribofuranosyl-1,2,4-triazole-3-carboxamide) is an effective antiviral agent against type A influenza infection of mice. Therapy was most effective when administered as a small-particle aerosol early in the infection. Treatment was also effective by either the intraperitoneal or aerosol route in mice with histological evidence of pneumonia. Ribavirin increased the percent survival, lowered lung virus titers, and decreased the development of lung pathology when therapy was initiated at 6 h as a small-particle aerosol. There was no evidence of pulmonary toxicity or immunosuppressive effects.