Abstract: Controlled release oral dosage forms are provided for the continuous, sustained administration of a pharmacologically active agent to the upper gastrointestinal tract of a patient in whom the fed mode as been induced. The majority of the agent is delivered, on an extended release basis, to the stomach, duodenum and upper regions of the small intestine, with drug delivery in the lower gastrointestinal tract and colon substantially restricted. The dosage form comprises a matrix of a biocompatible, hydrophilic, erodible polymer with an active agent incorporated therein, wherein the polymer is one that both swells in the presence of water and gradually erodes over a time period of hours, with swelling and erosion commencing upon contact with gastric fluid, and drug release rate primarily controlled by erosion rate.