← brief for 2026-09-13 · Transplant & xeno

Severe rise in tacrolimus levels following blood orange and grapefruit juice intake in a kidney transplant recipient: a case report.

Key takeaways

A 33-year-old man with a kidney transplant had a sharp jump in his blood level of tacrolimus, the drug that keeps his body from attacking the new kidney, after drinking blood orange juice and grapefruit juice. Grapefruit juice is already known to do this: it blocks a gut enzyme (CYP3A4) that breaks the drug down. This report points at blood orange juice too, which had not been reported before. It is a single person, so it shows a link, not proof of cause, but too much tacrolimus can damage the very kidney it is meant to protect.

Who did this work

Östman V (Department of Pharmacy, Uppsala University, Uppsala, Sweden. [email protected].) · Hamberg AK (Department of Pharmacy, Uppsala University, Uppsala, Sweden.) · Yamamoto S (Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.) · Lorant T (Department of Surgical Sciences, Uppsala University, Uppsala, Sweden.)

Source

Paper · Europe PMC, CKD · 2026-09-07
https://doi.org/10.1186/s13256-026-06514-w