title: Pharmacokinetics of ranitidine in preterm and term neonates with gastroesophageal reflux.
abstract: The aim of this study was to determine the effect of gestational age on pharmacokinetics of ranitidine in newborns with gastroesophageal reflux.
  
  
  
  A prospective, descriptive and pharmacokinetic study was carried out in 30 pre-term and 20 full-term babies. 3 mg/kg of ranitidine was administered intravenously to all the babies and at 0.25, 0.5, 1, 2, 4, and 8 h following the administration, samples of blood were drawn to assess ranitidine levels using high performance liquid chromatographic technique.
  
  
  
  Pharmacokinetics of ranitidine had a bi-exponential behavior with a half-life elimination of (t1/2el) 2.79 h, area under curve (AUC) of 1688 ng/mL, volume of distribution (Vd) of 1.44 L/kg, and clearance (Cl) of 5.9 L/kg/h. The median plasmatic concentration in pre-terms was 1113 ng/mL and 280 ng/mL in full-terms. Vd, t1/2 and Cl presented high values in preterm although the correlation of Cl with glomerular filtration in term newborns was better.
  
  
  
  Plasma levels of ranitidine depend on the gestational age of the newborns. However, the possible relationship between after-birth age and pharmacokinetics of the neonates as their internal organs get matured without minding their gestational background.
authors.affiliation: Interdisciplinary Centre of Investigation for Integral and Regional Development, Durango Unit, National Polytechnic Institute, Durango, Mexico.
authors.forename: Ismael Lares
authors.initials: IL
authors.lastname: Asseff
authors.affiliation: Pediatrics and Neonatology Services, General Hospital of Durango, Durango, Mexico.
authors.forename: Graciela Benitez
authors.initials: GB
authors.lastname: Gaucin
authors.affiliation: Laboratory of Pharmacology, National Institute of Pediatrics, and Department of Pharmacology, Faculty of Medicine, National Autonomous University of Mexico, Av Imán #1, 3er piso, Col Cuicuilco, CP 04530, Mexico City, Mexico. juarezol@yahoo.com.
authors.forename: Hugo Juárez
authors.initials: HJ
authors.lastname: Olguín
authors.affiliation: Interdisciplinary Centre of Investigation for Integral and Regional Development, Durango Unit, National Polytechnic Institute, Durango, Mexico.
authors.forename: Jose Antonio Godinez
authors.initials: JA
authors.lastname: Nájera
authors.affiliation: Laboratory of Pharmacology, National Institute of Pediatrics, and Department of Pharmacology, Faculty of Medicine, National Autonomous University of Mexico, Av Imán #1, 3er piso, Col Cuicuilco, CP 04530, Mexico City, Mexico.
authors.forename: Alejandra Toledo
authors.initials: AT
authors.lastname: López
authors.affiliation: Laboratory of Pharmacology, National Institute of Pediatrics, and Department of Pharmacology, Faculty of Medicine, National Autonomous University of Mexico, Av Imán #1, 3er piso, Col Cuicuilco, CP 04530, Mexico City, Mexico.
authors.forename: Gabriela Pérez
authors.initials: GP
authors.lastname: Guillé
authors.affiliation: Interdisciplinary Centre of Investigation for Integral and Regional Development, Durango Unit, National Polytechnic Institute, Durango, Mexico.
authors.forename: Fausto Zamura
authors.initials: FZ
authors.lastname: Torres
mesh_terms: D000897:Anti-Ulcer Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005764:Gastroesophageal Reflux / Q000097:blood / Q000188:drug therapy*; D005865:Gestational Age; D006207:Half-Life; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000097:blood / Q000188:drug therapy*; D007275:Injections, Intravenous; D008297:Male; D011446:Prospective Studies; D011899:Ranitidine / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use
chemical_list: D000897:Anti-Ulcer Agents; D011899:Ranitidine
keywords: Full-term; Gestational age; Neonates; Pharmacokinetics; Pre-term; Ranitidine