title: Azathioprine Therapy in a Pediatric TPMT-Deficient Patient-Still an Option.
abstract: We describe the case of a pediatric patient on azathioprine therapy with previously undiagnosed homozygote thiopurine S-methyltransferase (TPMT) deficiency, resulting in myelotoxic thiopurine metabolite levels. The patient was successfully treated with a very low azathioprine dose of 50 mg once a week (4% of standard dose), guided by frequent thiopurine metabolite measurement and a close clinical surveillance. We demonstrate that azathioprine therapy still might be an effective and safe therapeutic option in pediatric thiopurine S-methyltransferase-deficient IBD patients.
authors.affiliation: *Department of Clinical Pharmacy and Toxicology, Zuyderland Medical Centre, Sittard-Geleen;†Department of Pediatrics, Zuyderland Medical Centre, Heerlen; and‡Department of Clinical Pharmacy and Toxicology, Zuyderland Medical Centre, Heerlen, the Netherlands.
authors.forename: S A W
authors.initials: SA
authors.lastname: van Moorsel
authors.forename: N
authors.initials: N
authors.lastname: Bevers
authors.forename: M
authors.initials: M
authors.lastname: Meurs
authors.forename: L K
authors.initials: LK
authors.lastname: van Rossum
authors.forename: P M
authors.initials: PM
authors.lastname: Hooymans
authors.forename: D R
authors.initials: DR
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D001379:Azathioprine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004342:Drug Hypersensitivity / Q000150:complications* / Q000175:diagnosis; D016903:Drug Monitoring / Q000379:methods; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D008297:Male; D011686:Purine-Pyrimidine Metabolism, Inborn Errors / Q000150:complications* / Q000175:diagnosis; D016896:Treatment Outcome
chemical_list: D007166:Immunosuppressive Agents; D001379:Azathioprine