title: Pomelo-induced increase in the blood level of tacrolimus in a renal transplant patient.
abstract: BACKGROUND
  Tacrolimus, an immunosuppressive agent, is widely used in patients after transplantation to prevent allograft rejection. Because tacrolimus has a narrow therapeutic range, it is essential to carefully control the blood level. It has been demonstrated that tacrolimus is metabolized mainly by cytochrome P-450 (CYP) 3A4, and that tacrolimus is a substrate of P-glycoprotein.
  
  
  METHODS
  This article reports a case of considerable increase in the blood level of tacrolimus after the intake of pomelo in a renal transplant recipient.
  
  
  RESULTS
  Pomelo may increase the blood concentration of tacrolimus by inhibiting CYP 3A4, P-glycoprotein, or both.
  
  
  CONCLUSIONS
  Patients taking drugs such as tacrolimus or cyclosporine, which have their kinetics affected by grapefruit juice, should avoid pomelo and other grapefruit-related citrus fruits.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Kanoko
authors.initials: K
authors.lastname: Egashira
authors.forename: Etsuko
authors.initials: E
authors.lastname: Fukuda
authors.forename: Takayuki
authors.initials: T
authors.lastname: Onga
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yogi
authors.forename: Fukuzou
authors.initials: F
authors.lastname: Matsuya
authors.forename: Noriko
authors.initials: N
authors.lastname: Koyabu
authors.forename: Hisakazu
authors.initials: H
authors.lastname: Ohtani
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Sawada
mesh_terms: D000328:Adult; D002957:Citrus / Q000737:chemistry*; D004347:Drug Interactions; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood* / Q000627:therapeutic use; D016030:Kidney Transplantation; D008297:Male; D010936:Plant Extracts / Q000009:adverse effects*; D016559:Tacrolimus / Q000097:blood* / Q000627:therapeutic use
chemical_list: D007166:Immunosuppressive Agents; D010936:Plant Extracts; D016559:Tacrolimus