Tilorone hydrochloride: an orally active antiviral agent.

Tilorone hydrochloride, 2,7-bis[2-(diethylamino)ethoxy]fluoren-9-one dihydrochloride, given orally to mice before they are infected is active against at least nine viruses of both RNA and DNA groups. The compound is effective when given prophylactically; the optimum time of treatment depends on the route of infection.