The role of calcium-channel antagonists in solid organ transplantation.

Calcium-channel antagonists play a role not only in the management of cardiovascular disease, but they may also play a role in solid organ transplantation. Part of the success of solid organ transplantation over the last several years has been the development of potent immunosuppressive agents such as cyclosporine A and tacrolimus. The calcium-channel antagonists have been shown to decrease cyclosporine A-induced nephrotoxicity by blocking the vasoconstrictive effects of endothelin and thromboxane A2 on the afferent arteriole induced by this agent. The role of calcium antagonists in avoiding tacrolimus-induced nephrotoxicity has not been studied to date. Calcium antagonists have been shown to have an immune-modulating effect as well, via inhibition of calcium-mediated lymphocyte proliferation. This immune-modulating effect has resulted in a decreased incidence of acute rejection in those patients receiving concomitant cyclosporine and calcium antagonists. A third role for calcium antagonists in organ transplantation has been as an additive to organ preservation solutions to avoid calcium-mediated ischemic damage. Despite several successful investigations demonstrating a role for calcium antagonists in solid organ transplantation, widespread acceptance of such a role awaits larger randomized clinical trials.