In certain embodiments, the present disclosure is directed to methods and uses for treating a mammal having an epileptic seizure disorder or being at risk for having an epileptic seizure disorder, comprising administering certain herein disclosed isolated fenfluramine enantiomers that are surprisingly effective as anti-epilepsy drugs (AEDs), despite having lower anti-seizure potency than fenfluramine racemate, by virtue of also being less cardiotoxic than fenfluramine racemate. Preferred embodiments contemplate treatment of Dravet syndrome; other preferred embodiments contemplate treatment of other epileptic seizure disorders.