Background: In renal transplantation, triple-drug therapy (low-dose cyclosporine [CsA] combined with azathioprine plus steroids) has been replacing double-drug therapy (CsA plus steroids) in clinical practice without much evidence in favor of either therapy. Previous trials comparing the two immunosuppressive regimens gave conflicting results. We attempted to determine whether triple therapy is at least equivalent to double therapy.
Methods: A randomized trial was performed in 250 adult cadaveric renal transplant recipients, comparing double therapy (CsA [10 mg/kg/day] plus prednisone) with triple therapy (CsA [6 mg/kg/day] plus azathioprine plus prednisone). The median follow-up time was 930 days.
Results: The incidence of acute rejection episodes refractory to treatment was 11% in double therapy and 4% in triple therapy (relative risk reduction: 64%; 95% confidence interval: 5-100%; P=0.035). Patients in the double therapy group required more intensive antirejection treatment, and their pathologic lesions were more severe. The proportion of patients with acute rejection was similar (double therapy: 45% vs. triple therapy: 40%) as was the incidence of chronic renal dysfunction (double therapy: 17% vs. triple therapy: 15.5%), the 4-year graft survival (double therapy: 71% vs. triple therapy: 83%, P=0.089), and patient survival (double therapy: 94% vs. triple therapy: 93%). In 29 patients (23%), 35 episodes of azathioprine-induced leukopenia were recorded, and in 9 of them azathioprine had to be discontinued. The incidence of other adverse events did not differ between the groups.
Conclusions: Triple therapy caused fewer episodes of refractory acute rejection episodes and was as efficacious and safe as double therapy.