This article provides an extensive overview of the role and significance of immunosuppressive drugs in organ transplantation. It describes the molecular basis of graft recognition and rejection by the immune system and explains how various immunosuppressive agents act on different components of the immune response. The mechanisms, clinical applications, and advantages of calcineurin inhibitors, antiproliferative agents, corticosteroids, mTOR inhibitors, and biologics are discussed in detail. The article also highlights the risks associated with immunosuppressive therapy, including infections and malignancies, and emphasizes the importance of individualized dosing, pharmacokinetic monitoring, and combination regimens. This work is intended for specialists in transplantology, clinical pharmacology, and immunology.

Transplantation; immunosuppression; immunosuppressant drugs; calcineurin inhibitors; tacrolimus; cyclosporine; mycophenolate mofetil; corticosteroids; mTOR inhibitors; biologic therapy; rejection; HLA antigens; T lymphocytes; donor organ; transplant medicine.

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