Weight-based tacrolimus XR dose inconsistent among kidney transplant recipients
16 Feb 2023
In its third global initiative, WHO hopes to halve the number of medication errors by 2022.A weight-based dose of extended-release (XR) tacrolimus appears inadequate in predicting a therapeutic level among kidney transplant recipients due to the wide interpatient variability, according to a study.
“The median weight-based rate of conversion from immediate-release to extended-release tacrolimus was 80 percent,” the researchers said.
Adult kidney transplant recipients between July 2015 and December 2018 were eligible for inclusion in this retrospective, single-centre study. Patients who received dual organs, lacked appropriately drawn tacrolimus levels, or were prescribed interacting medications were excluded.
The researchers identified patients by querying prescriptions for tacrolimus XR and performed chart review to exclude those without sufficient follow-up following transition. Thirty patients who transitioned from immediate-release tacrolimus to tacrolimus XR were included.
The cohort achieved a therapeutic level with a median weight-based tacrolimus XR dose of 0.158 mg/kg/day (Q1‒Q3, 0.0587‒0.221), which was about 80 percent of the original median weight-based immediate-release tacrolimus dose.
A wide variability was noted in therapeutic dosing strategies, as represented by an R2 of 0.33 on linear regression. In addition, a statistically significant difference in median weight-based dosing strategies was observed among patients of various racial backgrounds (p=0.0148).
“Manufacturer recommendations for conversion from immediate-release to tacrolimus XR suggest 80 percent of the total daily dose of the immediate-release formulation,” the researchers said. “This conversion has not consistently achieved therapeutic levels in the kidney transplant population.”