This invention is directed to a method of treating substance addiction, including acute and post-acute withdrawal symptoms, comprising treating an addicted patient with ibogaine, ibogaine derivative, or a pharmaceutically acceptable salt and/or solvate thereof at a dosage that provides an average serum concentration of about 50 ng/mL to about 850 ng/mL under conditions where the QT interval prolongation does not exceed about 50 milliseconds.
