Omeprazole is a highly effective drug for the treatment of gastroesophageal reflux disease (GERD) in infants. Infants, aged 0-12 months, require a non-standard dose of omeprazole. Due to this fact extemporaneous formulations of omeprazole are administered to these infants. The oral bioavailability of omeprazole in nonproprietary formulations may be unpredictable and produce variable degrees of drug exposure. The dose range for GERD management in pediatric studies using omeprazole is 0.3 - 3.5 mg/kg/day.