Synergic action of distamycin A and hydroxyurea on the reproduction of DNA viruses in cell cultures.

The antiviral activity of the combination of distamycin A (DA) Pand hydroxyurea (HU) on the reproduction of vaccinia and pseudorabies viruses was investigated. The drug combination exerted a significant synergic inhibitory effect on the vaccinia virus yield and on the plaque formation in chick embryo cells. Similar experiments on pseudorabies virus showed an additive effect. The possible mechanism of the mutual enhancement of the antiviral activity is discussed.