Treatment of experimental cytomegalovirus infections with acyclovir

Subcutaneous (s.c.) administration of Acyclovir (ACV) (100 mg/1 kg bodyweight) resulted in an ACV blood level of 80 microM at 2 h post infection. Thereafter the level declined rapidly reaching undetectable levels at 12 h post infection. Administration of pro-ACV (100 mg/kg body weight) by s.c. or intravenous (i.v.) route resulted in ACV levels of 75 microM and 160 microM respectively after 30 min. But here again the blood level of ACV declined rapidly and was completely disappeared after 12 h. Continuous administration of pro-ACV in daily doses of 100, 250 and 350 mg/kg body weight resulted in ACV blood levels of 15 microM, 19 microM and 39 microM, respectively. The effect of ACV and pro-ACV on the replication of CMV was measured in immunesuppressed rats. In rats inoculated with RCMV the daily administration of 25 to 50 mg ACV per kg body weight by s.c. injections twice daily, did not result in a reduction of virus titers in spleen and liver, but when the RCMV-infected rats were treated by 100 mg pro-ACV per kg body weight virus titers in the spleen and liver were significantly reduced as compared with those in sham-treated animals.