Synergistic topical therapy by acyclovir and A1110U for herpes simplex virus induced zosteriform rash in mice

Combination therapy with A1110U, an inactivator of the herpes simplex virus (HSV) and the varicella zoster virus ribonucleotide reductase, and acyclovir (ACV) was evaluated for treatment of cutaneous herpetic disease in athymic mice infected on the dorsum. In this model, infection with HSV produces a ‘zosteriform-like’ rash that is first visible on day 3 or 4 post-infection (p.i.) and eventually extends from the anterior mid-line to the dorsal mid-line of the affected flank. In untreated mice, the infection is fatal at about day 7 p.i. presumably due to central nervous system involvement. Topical treatment of infections induced by either wild-type (wt) HSV-1 or wt HSV-2 with 3% A1110U in combination with 5% ACV resulted in synergistic ( P