Therapeutic Drug Monitoring in Solid Organ Transplantation

Therapeutic drug monitoring (TDM) is integral to the successful management of immunosuppressive therapy in solid organ transplantation. Calcineurin inhibitors such as tacrolimus and cyclosporine possess narrow therapeutic windows and exhibit high inter- and intra-patient pharmacokinetic variability. Precise dosing is required to prevent graft rejection while avoiding nephrotoxicity and other adverse effects. Modern TDM combines measurement of trough concentrations, population pharmacokinetic modelling, pharmacogenetic profiling and novel data-driven approaches. Pharmacogenetic markers (notably CYP3A5 genotype) inform initial dose selection, while dynamic monitoring of trough levels guides ongoing dose adjustments. Recent advances in computational modelling, high-throughput omics and interaction studies have expanded the toolkit for individualising immunosuppression. Globally, these developments promise to improve graft survival, reduce toxicity and streamline clinical workflows in diverse transplant settings.

Research from Nature Portfolio

Recent studies have harnessed machine-learning algorithms to refine dose prediction for tacrolimus in renal transplant recipients. A landmark investigation compared multiple regression and eight advanced computational models in a large cohort, identifying regression tree analysis as the superior tool for forecasting stable tacrolimus exposure. By integrating demographic, clinical and pharmacogenomic variables, this work demonstrates how data-driven algorithms can enhance personalised dosing, shorten the time to therapeutic concentrations and potentially reduce incidence of rejection and nephrotoxicity.

Therapeutic Drug Monitoring in Solid Organ Transplantation publication trend

The graph below shows the total number of articles in therapeutic drug monitoring in solid organ transplantation across all publications each year (not limited to Nature Index journals).

Technical terms

Therapeutic window: Range of drug concentration associated with optimal efficacy and minimal toxicity.

Trough concentration (C₀): Lowest blood drug level measured immediately before the next dose, used to assess exposure.

Calcineurin inhibitor (CNI): Class of immunosuppressants (e.g. tacrolimus, cyclosporine) that inhibit T-cell activation but carry nephrotoxic risk.

Pharmacogenetics: Study of how genetic polymorphisms (e.g. CYP3A5 variants) influence individual drug metabolism and response.

C/D ratio: Dose-normalised trough concentration (concentration/dose), a simple metric to identify fast or slow metaboliser status.

References

1. Fixed low dose versus concentration-controlled initial tacrolimus dosing with reduced target levels in the course after kidney transplantation: results from a prospective randomized controlled non-inferiority trial (Slow & Low study). EClinicalMedicine (2023).
2. A multi-omics investigation of tacrolimus off-target effects on a proximal tubule cell-line. Pharmacological Research (2023).
3. Safety analysis of co-administering tacrolimus and omeprazole in renal transplant recipients – A review. Biomedicine & Pharmacotherapy (2023).
4. Application of Machine-Learning Models to Predict Tacrolimus Stable Dose in Renal Transplant Recipients. Scientific Reports (2017).
5. Impact of the CYP3A5, CYP3A4, COMT, IL-10 and POR Genetic Polymorphisms on Tacrolimus Metabolism in Chinese Renal Transplant Recipients. PLOS ONE (2014).
6. Tacrolimus Updated Guidelines through popPK Modeling: How to Benefit More from CYP3A Pre-emptive Genotyping Prior to Kidney Transplantation. Frontiers in Pharmacology (2017).