Combination drug therapies for immunosuppression in transplantation

Current combination immunosuppression protocols used worldwide include azathioprine/prednisolone, cyclosporine protocols, cyclophosphamide/steroids and FK506/steroids. The fact that many different immunosuppression protocols are currently in use, demonstrates that none is ideal. Major determinants in the choice of any protocol include graft and patient survival, side effects and cost. While most protocols may offer one year graft survival rates of 80% to 90% in renal transplantation, it is the long term results which are becoming increasingly important, but as many protocols have only been recently introduced, it may be sometime before these answers are known. While the most effective regimens include cyclosporine, long term nephrotoxicity remains a problem. Furthermore, the cost of the drug may be prohibitive in many countries worldwide. Azathioprine and low dose steroids still provide acceptable results with lesser expense and where cost and drug availability are critical, cyclophosphamide may even be introduced in place of azathioprine in living-related renal transplant recipients. The role of the newer immunosuppressive agents such as FK506 remains unclear, as the results of prospective randomised studies are not yet available. With excellent results now obtained with many different protocols, it is apparent that the choice of the most suitable immunosuppressive regimen is no longer dictated by graft survival alone.