Pharmacokinetic Study of Esomeprazole Magnesium in Patients 1 to 11 Years-Old With Endoscopically-Proven Gastroesophageal Reflux Disease (GERD)

Inclusion Criteria: * Patients must be able to take solid or bland food (eg, applesauce). * Patients must weigh at least 8 kg and at the investigator's discretion be able to undergo extraction of an adequate volume of blood. * The patient's weight for height percentile should be less than the 90th percentile and/or the BMI must be between the 5th and 85th percentile for age. * Patients must be diagnosed with endoscopically-proven GERD Exclusion Criteria: * Use of any other investigational compound or participation in another clinical trial within 28 days prior to the screening visit. * History or presence of gastrointestinal, hepatic or renal disease or other conditions that could interfere with absorption, distribution, metabolism or excretion of esomeprazole. * Unstable diabetes mellitus or history of seizure disorder. * Any acute or chronic illness or a medical history, which in the opinion of the investigator and/or sponsor, could compromise the patient's safety or successful participation in the study.