Does the switch from Sandimmun to Sandimmun Neoral reduce patient need for Phenihydine?

In patients receiving cyclosporine A (CyA) - based immunosuppressive therapy, Ca²⁺ channel blockers (CCBs) prevent the development of CyA - related nephrotoxicity in which increased Ca²⁺ content plays an important role. We evaluated the dynamics of the intracellular (erythrocytes) and extracellular (plasma) Ca²⁺ levels and the influence of the CCB, Phenihydine, on this process during the conversion from Sandimmun (S) to Sandimmun Neoral (SN). Forty-two patients were enrolled. The conversion from S to SN normalized the elevated CA²⁺ level of erythrocytes in groups with Phenihydine (n = 20) and without Phenyhidine (n = 12) 4 weeks after the switch (P < 0.05); this level remained stable until the end of study. Therefore we suggest that the switch from S to SN is effective in reducing elevated intracellular Ca²⁺ levels. The decrease of Ca²⁺ content in erythrocytes was similar in all groups switched to SN (with or without Phenihydine). The last effect should be an important argument to focus the further long-term investigations on the ability of CCBs to act as cytoprotective and nephroprotective agents during immunosuppressive protocols with the new microemulsion formulation of CyA.