Erro R, et al. - Given that tremor is the most frequent and disabling neurological side effect under Calcineurin inhibitor-induced immunosuppression, the researchers attempted to define its phenomenology, severity, distribution, the impact on quality of life, as well as of other neurological symptoms associated. They enrolled one hundred twenty-six consecutive kidney-transplanted patients, under treatment with Cyclosporin A, Tacrolimus and non-Calcineurin inhibitors, within therapeutic range. Findings revealed that non-Calcineurin inhibitors such as Sirolimus have the lowest propensity to induce tremor and with a milder severity. On the other hand, Calcineurin inhibitors, especially Tacrolimus, the highest, and regardless of the formulation. They discovered that plasmatic concentration of Tacrolimus was higher in tremulous patients.