A variety of drugs are used in the neonatal nursery for the management of feeding intolerance, gastroesophageal reflux, and acid-related disease. Although the pharmacokinetics of some of these drugs have been described in infants and older children, further data are needed, particularly for preterm infants. No data are available characterizing the disposition of the proton pump inhibitors, which will likely be used in infants with refractory, acid-related disease. Further data are also needed to characterize fully the pharmacodynamics, or efficacy, of many of the commonly used drugs.