The objective of this study is to evaluate the efficacy, acceptability, and safety of Axid Oral Solution versus placebo in the treatment of gastroesophageal reflux disease (GERD) in infants age 30 days up to 1 year.

Inclusion Criteria:

• Male or female outpatients age 30 days up to 1 year at Visit 1.
• Subjects must have a documented medical diagnosis of gastroesophageal reflux disease (GERD), confirmed by either endoscopy or pH monitoring, or by evaluation of baseline symptoms.
• Subjects must be greater than the 3rd percentile of weight and height for their age.
• Parents/guardians are competent and willing to provide consent and sign and date the institutional review board (IRB) approved consent form.
• Parents/guardians are willing to adhere to study requirements, including applying the conservative GERD management methods.
• Conservative GERD management methods have failed to adequately control GERD symptoms by Visit 2.
• Parent/guardian and infant live in the same household.
• Qualifying caregiver questionnaire score at Visits 1 & 2.

Exclusion Criteria:

• Any known esophageal disease or disorder, other than reflux esophagitis.
• Any active gastroduodenal ulceration, or clinical or endoscopic evidence of active gastrointestinal bleeding.
• Any prior esophageal or gastric surgery.
• Concurrent serious systemic disorders, including chronic respiratory disease, chronic neurologic disease, chronic renal disease, chronic liver disease.
• Subjects with clinically significant abnormal laboratory findings at screening.
• Premature infants < 37 weeks gestation at birth.
• Infants with prior neonatal intensive care unit admission for any reason.
• Hematemesis or apparent life-threatening events (ALTE).
• Concurrent treatment with any chronic medication except by permission of the study sponsor.
• Treatment with a histamine 2 receptor antagonist (H2RA), antacid, sucralfate, prostaglandin, or motility agent within 3 days before Visit 1; treatment with a proton pump inhibitor within 7 days before Visit 1.
• Requirement or likely requirement for a medical procedure or surgery during the study.
• Known hypersensitivity to an H2RA including nizatidine.
• Receipt of any investigational agent within the previous 30 days before randomization.
• Poor medical or psychiatric risks for therapy with an investigational drug, in the opinion of the investigator.
• Any condition in parent/guardian associated with poor subject compliance e.g., substance abuse); inability of parent/guardian to return for scheduled visits with their child.