Co-administration of Diltiazem and Cyclosporine for Kidney Transplant Recipients : A Four Year Follow-Up Study
Atiporn Ingsathit MD, PhD*, Vasant Sumethkul MD*, Panas Chalermsanyakorn MD**, Sophon Jirasiritham MD***
Affiliation : * Department of Medicine,** Pathology, *** Surgery Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Thailand
Background : Diltiazem and cyclosporin A (CsA) share a similar metabolism and degradation via the hepatic
cytochrome p 450 subfamily 3A4. Co-administration of diltiazem with CsA may lead to CsA dosage reduction,
blood pressure control and renal protection.
Objectives : To study the four year outcome of kidney transplant recipients who received diltiazem administra-
tion with CsA. This was compared to the outcomes of patients who received CsA without diltiazem and were
matched for blood pressure control and other baseline characteristics.
Materials and Methods : Forty eight patients were included in the diltiazem group and seventy patients in the
non-diltiazem group. CsA monitoring was done by using trough level (monoclonal fluorescent polarization
immunoassay).
Results : The results showed that both groups has similar 4-year graft survival (92 and 95 %) with a similar
mean final serum creatinine (1.3 mg/dl). Mean dose of CsA during the first month was 30 % lower in the
diltiazem than non-diltiazem group. At one year, CsA dose was 11% lower in the diltiazem than non-diltiazem
group. However, the diltiazem group was associated with significantly higher probability to have chronic
allograft nephropathy than the non-diltiazem group (31% VS 19%) (RR 2.93; p = 0.03; Multivariate Cox
regression).
Conclusion : Co administration of diltiazem with trough level adjusted CsA is associated with benefits in terms
of CsA dose reduction and good graft survival and function. However, there appeared to be no protective effect
of diltiazem on the progression to chronic allograft nephropathy.
Keywords : Cyclosporine, Diltiazem, Kidney transplantation, Chronic allograft nephropathy
