A PHARMACEUTICAL COMPOSITION FOR TOPICAL ADMINISTRATION COMPRISING 2,3-DIMETHYL-6-(N,N-DIMETHYLAMINOETHYL)-6H-INDOLO-(2,3-B)QUINOXALINE (B-220) OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF IN A PHARMACEUTICALLY ACCEPTABLE CARRIER. THE COMPOSITION IS USEFUL FOR THE TREATMENT OF HERPES VIRUS INFECTIONS OF THE SKIN OR MUCOUS MEMBRANES IN A MAMMAL SUBJECT. (NO SUITABLE FIGURE)