Safety and Quality of Life Study of Dexlansoprazole Modified Release Formulation to Treat Heartburn

Inclusion Criteria: Subjects must have successfully completed either T-GD04-082 (NCT00251745) or T-GD04-083 (NCT00251758) or have a diagnosis of gastroesophageal reflux disease with or without erosive esophagitis. Exclusion Criteria: Any condition that may require inpatient surgery during the course of the study. Use of prescription or non-prescription proton pump inhibitors, histamine (H2) receptor antagonists, sucralfate, misoprostol or prokinetics throughout the study. Use of antacids [except for study supplied Gelusil®]. Subjects using drugs with significant anticholinergic effects such as tricyclics who cannot stay on a stable dose for 4 weeks prior to dosing and throughout the study. Evidence of uncontrolled systemic disease. Allergy to any proton pump inhibitor including Prilosec, Nexium, Prevacid, or others, any component of dexlansoprazole MR, or Gelusil/antacid. Need to take blood thinners. Need to take more than 12 doses of non-steroidal anti-inflammatory drugs per month. Had cancer (except basal cell cancer of the skin) within 3 years prior to screening. Has other esophageal disease including Barrett's esophagus or strictures requiring dilation. Has had radiation or cryotherapy to the esophagus. Has active gastric or duodenal ulcers within 4 weeks of starting study drug. Has a history of hypersecretory conditions such as Zollinger Ellison Syndrome. History of alcohol abuse. Has acquired immunodeficiency syndrome. Has had acute upper gastrointestinal bleeding within 4 weeks of endoscopy. Received a blood product transfusion within 3 months of taking the first dose of study drug. Has previously participated in another dexlansoprazole MR long-term treatment clinical trial.