A Controlled, Double-Blind, Randomized Trial of Verapamil and Cyclosporine in Cadaver Renal Transplant Patients

Calcium channel blockers have immunomodulating effects in vitro and may be effective in preventing cyclosporine nephrotoxicity. We studied the effect of verapamil following renal transplantation on the incidence of rejection and cyclosporine nephrotoxicity in a double-blind, placebo-controlled trial. Patients were randomly assigned to placebo (n = 28) or verapamil (n = 32) at doses of 80 mg twice a day. There was no difference in the incidence of rejection or cyclosporine toxicity in the two study arms. Recipients randomized to verapamil had lower mean cyclosporine doses at all intervals during a 1-year follow-up. Although cyclosporine doses were lower in the placebo group, the mean cyclosporine levels were equivalent in the two groups. Recipients in the verapamil-treated group had a higher mean serum creatinine at the end of the study--1.7 mg/dL versus 1.4 mg/dL in the placebo group. Actual 1-year graft survival was 89% for the placebo recipients versus 91% in the verapamil-treatment group. When compared with placebo, the concomitant use of low-dose verapamil results in lower cyclosporine doses but equivalent cyclosporine blood levels. Reduction in the incidence of rejection or cyclosporine nephrotoxicity were not observed.