Potential Drug-Drug Interactions in Kidney Transplant Patients

Introduction:

Beside immunosuppressive therapy, transplant patients frequently require a complex drug regimen that may consist of many drugs. Maintenance immunosuppression usually involves a combination of 2 or 3 agents.

Objectives:

The objectives were to identify potential drug-drug interactions (pDDI) and evaluate their prevalence in kidney transplant patients.

Study Design:

The data for 105 adult patients over the period of maximum 5 years after transplantation, were collected from medical charts in the Nephrology Clinic, Clinical Centre of Serbia, University of Belgrade. All patients were informed and allowed the using of their charts.

Methods:

pDDIs were evaluated using Lexicomp^® data base and data were analyzed using IBM SPSS Statistics 22^®. 

Results:

A total of 5788 prescriptions were evaluated. The median number of drugs per patients was 6, with minimum of 3 and maximum of 11 drugs per patients. The number of therapy regimens without identified interactions were 83. Total number of detected pDDIs was 2887. The pDDIs were classified according the Lexicomp^® risk rating. The number of pDDIs in every category was: 215 in B (no action needed), 2420 in C (monitor therapy), 237 in D (modify regimen) and 15 in X (avoid combination). The drug included in the most of pDDIs classified as X (86,67%) was tacrolimus (TAC). The most frequent interactions in D category were TAC and omeprazole, TAC and esomeprazole and amlodipine and simvastatin.

Conclusions:

The number of pDDIs in kidney transplanted patients is significant. More attention for clinically significant interactions is warranted in this population in order to provide safer and more effective therapy.