title: Understanding intestinal cysteamine bitartrate absorption.
abstract: OBJECTIVE
  To test the hypothesis that a controlled-release preparation of cysteamine, with fewer daily administrations, would improve the quality of life for patients with cystinosis.
  
  
  METHODS
  A specifically designed nasoenteric tube was used to administer cysteamine directly into the stomach, small intestine (SI) and colon and serial plasma cysteamine, serum gastrin and leukocyte cystine levels were measured.
  
  
  RESULTS
  Eight control subjects (mean age 23.2 years) and 6 subjects with cystinosis (mean age 15.2 years) were studied. Cysteamine absorption (maximum concentration and area under the curve of the concentration-time gradient) was greater from the SI than stomach or cecum (P < .01). Leukocyte cystine depletion was greater after delivery of cysteamine into the SI than stomach or cecum; this effect was associated with the plasma cysteamine maximum concentration and area under the curve (P < .001 and < .02, respectively). Gastrin levels were not affected by site of drug delivery and were elevated only in patients with cystinosis with gastrointestinal symptoms.
  
  
  CONCLUSIONS
  The absorption of cysteamine and the effect of this agent on leukocyte cystine depletion are more profound after SI administration. Enteric-coated cysteamine, targeted for SI release, may require fewer daily dosages. Not all patients with cystinosis require acid-suppression therapy.
authors.affiliation: Department of Pediatrics, University of California, San Diego, La Jolla, California 92103-8450, USA. rdohil@ucsd.edu
authors.forename: Ranjan
authors.initials: R
authors.lastname: Dohil
authors.forename: Meredith
authors.initials: M
authors.lastname: Fidler
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Barshop
authors.forename: Jon
authors.initials: J
authors.lastname: Gangoiti
authors.forename: Reena
authors.initials: R
authors.lastname: Deutsch
authors.forename: Michael
authors.initials: M
authors.lastname: Martin
authors.forename: Jerry A
authors.initials: JA
authors.lastname: Schneider
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D003543:Cysteamine / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D003553:Cystine / Q000032:analysis; D003554:Cystinosis / Q000188:drug therapy* / Q000378:metabolism; D003692:Delayed-Action Preparations; D005260:Female; D005755:Gastrins / Q000097:blood; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D007962:Leukocytes / Q000737:chemistry; D008297:Male; D011788:Quality of Life
chemical_list: D003692:Delayed-Action Preparations; D005755:Gastrins; D003553:Cystine; D003543:Cysteamine