Medicine
Pharmacokinetic Variability of Tacrolimus in Renal Transplant Recipients
Quick fact
African-American renal transplant recipients, who often carry a variant of the CYP3A5 gene, typically need 1.5 to 2 times higher tacrolimus doses than non-expressers to achieve the same blood level. This difference is so pronounced that the FDA-approved label recommends genotype-based dose selection.
Why this is interesting
You might think a fixed drug dose works similarly for everyone—but for tacrolimus, two patients receiving the exact same amount can have blood levels that differ by over 100-fold. Why does the same pill behave so differently?