Idoxuridine has been employed in the treatment of herpes simplex encephalitis with good results in patients treated early in the disease and receiving the full therapeutic course of the agent. Despite early and complete therapy with the agent (400 mg/kg) the disease course was unaltered in this case and the patient died after the fifth day of therapy. The herpes simplex virus was isolated from specimens of the brain and was visualized in the tissue on electron microscopic examination.
Fishman MA, Haymond MW, Middelkamp JN. Failure of Idoxuridine Treatment in Herpes Simplex Encephalitis. Am J Dis Child. 1971;122(3):250–252. doi:10.1001/archpedi.1971.02110030108017