Tacrolimus Monitoring in Hair Samples of Kidney Transplant Recipients

This study quantified tacrolimus levels in the scalp hair of 39 kidney transplant recipients, finding detectable levels in 98% of samples with a median concentration of 7.0 pg/mg. There was a positive, though not statistically significant, correlation between hair tacrolimus levels and daily dose. Hair analysis reflected recent medication changes, suggesting its potential for long-term drug monitoring. The study noted that hair color and patient age significantly influenced tacrolimus levels, with higher concentrations in darker hair and lower levels in older patients. Despite the small cohort and single-time point evaluations, the method offers a non-invasive alternative for therapeutic drug monitoring. Further research is needed to establish therapeutic targets and understand confounders.