title: Pharmacodynamics and systemic exposure of esomeprazole in preterm infants and term neonates with gastroesophageal reflux disease.
abstract: OBJECTIVE
  To characterize the pharmacodynamics and systemic exposure of esomeprazole in 26 preterm infants and term neonates with symptoms of gastroesophageal reflux and pathologic acid exposure.
  
  
  METHODS
  Enrolled patients received oral esomeprazole 0.5 mg/kg once daily for 7 days. Twenty-four-hour esophagogastric pH-impedance monitoring was performed at baseline and on day 7. Pharmacokinetic analysis was performed on day 7. Symptoms occurring during the baseline and day 7 studies were recorded on a symptom chart.
  
  
  RESULTS
  There were no significant differences from baseline to day 7 of therapy in the frequency of bolus reflux, consistency of bolus reflux (liquid, mixed, or gas), extent of bolus reflux, or bolus clearance time. Acid bolus reflux episodes were reduced on therapy (median 30 vs 8, P < .001), as was the reflux index (mean % time esophageal pH < 4, 15.7% vs 7.1%, P < .001). The estimated geometric mean of area under the plasma concentration time curve during the dosing interval and observed maximum plasma concentration was 2.5 micromol x h/L and 0.74 micromol/L, respectively. The number of gastroesophageal reflux symptoms recorded over 24 hours was lower on therapy (median 22 vs 12, P < .05).
  
  
  CONCLUSIONS
  In preterm infants and term neonates esomeprazole produces no change in bolus reflux characteristics despite significant acid suppression.
authors.affiliation: Gastroenterology Unit, Children, Youth and Women's Health Services, North Adelaide, SA, Australia. taher.omari@adelaide.edu.au
authors.forename: Taher
authors.initials: T
authors.lastname: Omari
authors.forename: Per
authors.initials: P
authors.lastname: Lundborg
authors.forename: Marie
authors.initials: M
authors.lastname: Sandström
authors.forename: Patrik
authors.initials: P
authors.lastname: Bondarov
authors.forename: Mia
authors.initials: M
authors.lastname: Fjellman
authors.forename: Ross
authors.initials: R
authors.lastname: Haslam
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Davidson
mesh_terms: D000284:Administration, Oral; D000897:Anti-Ulcer Agents / Q000097:blood* / Q000627:therapeutic use*; D003448:Crying; D017097:Electric Impedance; D064098:Esomeprazole / Q000097:blood* / Q000627:therapeutic use*; D050782:Esophageal pH Monitoring; D005260:Female; D005502:Food; D005683:Gagging / Q000187:drug effects; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007508:Irritable Mood / Q000187:drug effects; D008297:Male; D014839:Vomiting / Q000517:prevention & control
chemical_list: D000897:Anti-Ulcer Agents; D064098:Esomeprazole