Immunosuppressants are class of drugs that supress the endurance of the body’s immune system in order to minimize the risk of rejection foreign bodies such as transplant organs. Furthermore they are used in the treatment of autoimmune disorders. Quantification of immunosuppressive drugs analysis in blood is a key application of the therapeutic drug monitoring (TDM) approach which is crucial for the prevention of adverse drug reactions and rejection events due to incorrect dosage. Immunosuppressive drug therapy is limited within a narrow therapeutic window whose borders are drawn by rejection at low exposure and toxic influence at high exposures. Currently, several analytical methods have been developed for the determination of immunosuppressive drugs based on immunoassays (IAs) such as fluorescence polarization immunoassay (FPIA), microparticle enzyme immunoassay (MEIA) etc. and liquid chromatography with tandem mass spectrometry (LC–MS/MS). Due to achievement low quantification limits with adequate specificity and high selectivity, LC-MS/MS is the preffered technique for the analysis of immunosuppressant drugs.

Jasem method provides analysis of Tacrolimus, Sirolimus, Evorilimus and Cyclosporine A in whole blood specimen by straightforward sample preparation followed LC-MS/MS analysis.