Influence of pill burden and drug cost on renal function after transplantation.

Objective: To determine the influence of pill burden and drug cost on outcomes after renal transplantation.

Methods: Retrospective medical record review. Methods: Kidney and pancreas transplantation center. Methods: Sixty-eight adults who underwent kidney or kidney-pancreas transplantation during 2007.

Results: The median pretransplantation pill burden was 15 pills/day, which increased to 25 pills/day at 1 month after transplantation and returned to 16 pills/day by 1 year after transplantation. Pretransplantation pill burden was lower than the burden at 1, 3, 6, 12, and 24 months after transplantation (p<0.05). The mean pretransplantation drug cost of $1918/month was lower than the cost at 1 month after transplantation ($2564/mo, p=0.04) but was similar thereafter. Higher pretransplantation pill burden was associated with increased serum creatinine concentration at 6 months after transplantation (r=0.288, p=0.017). Higher pill burdens at 1 month (r=0.364, p=0.002), 3 months (r=0.332, p=0.006), and 6 months (r=0.374, p=0.002) were associated with increased 3-month serum creatinine concentration. Higher drug costs were associated with increased serum creatinine concentrations throughout the study.

Conclusions: Higher pretransplantation pill burden and higher drug cost may be associated with poor renal function after transplantation. Further study addressing factors associated with nonadherence is needed.