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Pomelo-induced increase in the blood level of tacrolimus in a renal transplant patient

Egashira, Kanoko1; Fukuda, Etsuko3; Onga, Takayuki3; Yogi, Yasuo3; Matsuya, Fukuzou3; Koyabu, Noriko1; Ohtani, Hisakazu1; Sawada, Yasufumi1 2

doi: 10.1097/01.TP.0000058545.35041.BE
BRIEF COMMUNICATIONS: Clinical Transplantation

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.

1 Graduate School of Pharmaceutical Sciences, Kyushu University, Japan.

2 Address correspondence to: Yasufumi Sawada, Ph.D., Professor, Department of Medico-Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, 3–1-1 Maidashi, Higashi-ku, Fukuoka 812–8582, Japan. E-mail:

3 Department of Pharmacy, National Nagasaki Medical Center, 2–1001–1 Kubara, Omura, Nagasaki 856–8562, Japan.

Received 23 October 2002.

Accepted 3 December 2002.

© 2003 Lippincott Williams & Wilkins, Inc.