A Comprehensive Mixed-Method Approach to Characterize the Source of Diurnal Tacrolimus Exposure Variability in...

Area of Science:

• Pharmacology
• Pediatric Nephrology
• Chronopharmacology

Background:

• Tacrolimus pharmacokinetics often show diurnal variation with twice-daily dosing.
• The influence of chronopharmacokinetics versus food intake on tacrolimus exposure is not well-defined, especially in pediatric populations.

Approach:

• A meta-analysis of 10 studies (253 pediatric kidney transplant recipients) was conducted.
• Pharmacokinetic parameters were evaluated, including the impact of food composition on 24-hour exposure.
• A 2-compartment model was used to characterize tacrolimus pharmacokinetics.

Key Points:

• Significant differences in area under the concentration-time curve and maximum concentration were observed between morning and evening dosing.
• Food exposure was identified as a significant source of between-study heterogeneity.
• Caloric composition of food significantly reduced variability in lag time, suggesting food intake is a major driver of diurnal variation.

Conclusions:

• Food intake, particularly caloric content, is the primary driver of diurnal tacrolimus exposure variations in pediatric kidney transplant recipients.
• Trough concentrations may not adequately reflect the full impact of food on tacrolimus exposure.
• Understanding these factors is crucial for optimizing tacrolimus dosing strategies in pediatric patients.