CMV retinitis Drugs used to treat CMV retinitis in induction and maintenance regimens include Ganciclovir or valganciclovir Foscarnet, with or without ganciclovir Cidofovir Most patients receive induction therapy with one of the following: Ganciclovir 5 mg / kg IV every 12 hours for 2 to 3 weeks Valganciclovir 900 mg orally every 12 hours for 21 days If induction fails more than once, another drug should be used.