Severe rise in tacrolimus levels following blood orange and grapefruit juice intake in a kidney transplant recipient: a case report.
Victoria Östman, Anna-Karin Hamberg, Shinji Yamamoto et al.
✦ AI-curated · Sources linked
Case in brief
A 33-year-old male kidney transplant recipient experienced persistently low tacrolimus levels despite increased dosing. After consuming one liter of blood orange juice followed by grapefruit juice, his tacrolimus concentration surged to 30 µg/L, leading to a kidney biopsy that revealed eosinophilic infiltration. Tacrolimus therapy was temporarily halted and then gradually reintroduced, resulting in stabilization and discharge on postoperative day 12.
What made this case unusual
The significant rise in tacrolimus levels following the intake of blood orange juice, which has not been previously documented to affect tacrolimus pharmacokinetics, suggests a potential interaction with grapefruit juice.
Diagnostic / clinical pearl
Clinicians should consider the impact of dietary factors, such as blood orange and grapefruit juice, on tacrolimus levels in kidney transplant patients due to their effects on CYP3A4 and CYP3A5.
Why it matters
This case highlights the importance of obtaining a detailed dietary history in transplant patients to prevent potential drug interactions that could lead to adverse outcomes.