Therapeutic effect of pyrophosphate analogues on cutaneous herpes simplex virus type 1 infection in guinea pigs.

We investigated the influence of disodium phosphonic formate (PFA-Na2) and trisodium thiophosphonic formate (TPFA-Na3), in comparison with acyclovir (Zovirax) and trisodium phosphonic formate (PFA-Na3) (Triapten) ointment, on the course of primary cutaneous herpes simplex virus infection in a guinea pig skin model. PFA-Na2 at 3.0%, TPFA-Na3 at 0.5% and PFA-Na3 at 0.5% as well as Triapten ointment (2.0% PFA-Na3) completely inhibited virus infection. Zovirax cream (5.0% acyclovir), applied five times (15 min., 4, 20, 24, and 28 h) after virus inoculation did not prevent virus infection. Similarly, application of Zovirax cream 5 times daily for 5 days did not prevent a vesicle formation following cutaneous herpes simplex virus infection of the guinea pig.