The invention relates to dosage forms that provide prolonged therapy. In particular, the invention relates to dosage forms including various pluralities of drug-containing resin particles. In a particular embodiment, the drug dosage form comprises a mixture of dextro- and levo-amphetamines complexed with ion-exchange resin particles to form drug resin particles. The invention also relates to methods of making these dosage forms and methods of treating using these dosage forms.
