<prompt> Drug not used in CMV retinitis:AcyclovirFoscarnetGanciclovirCidofovir  <response>: Ref: Goodman Gillmans 13th ed. P 1106-7 Acyclovirs clinical use is limited to herpes viruses. Acyclovir is most active against HSV-1. Approximately half as active against HSV-2, and a tenth as potent against VZV and EBV. Book states: Acyclovir is ineffective therapeutically in established CMV infections, but ganciclovir is effective for CMV prophylaxis in immunocompromised patients EBV-related oral hairy leukoplakia may improve with acyclovir. Drugs which can be used in treatment of CMV retinitis are cidofovir, ganciclovir, foscarnet, valaciclovir. DOC for CMV retinitis: Ganciclovir Fomivirsen is active against CMV strains resistant to ganciclovir, foscarnet, and cidofovir. Fomivirsen is given by intravitreal injection unresponsive to other therapies. 