Cardiac transplant experience with cyclosporine.

The advent of cyclosporine 20 years ago was a major advance in the field of solid organ transplantation. Its use enabled directed immunosuppression with a consequent decrease in the incidence of graft failure, acute rejection, and systemic infection. The early oil-based preparation, however, was difficult to administer and had limited bioavailability and unpredictable pharmacokinetics. The drug also has a fairly narrow therapeutic window with major long-term side effects, which include nephrotoxicity, malignancy, hyperlipidemia, and hypertension. The introduction of a microemulsion preparation (Neoral) with improved bioavailability has been associated with lower rates of rejection and comparable tolerability, therefore allowing the use of lower doses. Traditionally cyclosporine toxicity has been minimized by monitoring trough levels. Monitoring of levels 2 hours after dosing may provide a more accurate determination of cyclosporine exposure. The next phase in cardiac transplantation immunosuppression will most likely see a significantly diminished role for cyclosporine with the introduction of newer, more potent immunosuppressive agents with more favorable side-effect profiles. These agents, which include mycophenolate mofetil, sirolimus, and everolimus, also hold the promise of having a major impact on the development of transplant vasculopathy, which up to now has been an important determinant of limiting long-term allograft survival.