title: Treatment of cystinosis with delayed-release cysteamine: 6-year follow-up.
abstract: BACKGROUND
  Patients with nephropathic cystinosis are required to take 6-hourly immediate-release cysteamine (Cystagon®) to reduce disease progression. This arduous regimen affects quality of life, disrupts sleep, and may result in non-compliance with therapy. Enteric-coated cysteamine bitartrate (EC-cysteamine) was developed as a "proof-of-concept" formulation for twice-daily ingestion. Previous reports have shown this therapy to be effective up to a mean of 14 months.
  
  
  METHODS
  Two subjects (aged 13 and 15 years) received EC-cysteamine for 5-6 years at 60-65 % of their previous total daily dose of immediate-release cysteamine given at 6-h intervals. White blood cell (WBC) cystine levels were monitored every 1-3 months.
  
  
  CONCLUSIONS
  The administration of EC-cysteamine did not result in any change in mean trough WBC cystine levels or any deterioration in the estimated glomerular filtration rate, thyroid, or liver function, suggesting that delayed-release, twice-daily EC-cysteamine is an effective long-term treatment alternative to immediate-release cysteamine given at 6-h intervals.
authors.affiliation: Department of Pediatrics, Rady Children's Hospital-San Diego, University of California San Diego, 3030 Children's Way, San Diego, CA 92123, USA. rdohil@ucsd.edu
authors.forename: Ranjan
authors.initials: R
authors.lastname: Dohil
authors.forename: Betty L
authors.initials: BL
authors.lastname: Cabrera
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D002626:Chemistry, Pharmaceutical; D003404:Creatinine / Q000097:blood; D003543:Cysteamine / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D003554:Cystinosis / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D003692:Delayed-Action Preparations; D004334:Drug Administration Schedule; D005198:Fanconi Syndrome / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006801:Humans; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D007958:Leukocyte Count; D008297:Male; D009404:Nephrotic Syndrome / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D003692:Delayed-Action Preparations; D003543:Cysteamine; D003404:Creatinine