Rimantadine (sold under the trade name Flumadine) is an orally administered antiviral drug used to treat, and in rare cases prevent, Influenzavirus A infection. When taken within one to two days of developing symptoms, rimantadine can shorten the duration and moderate the severity of influenza. It is a derivate of adamantane, like a similar drug amantadine. It was approved by the Food and Drug Administration (FDA) in 1994.. For rest of text click here. ...