Problems associated with the use and monitoring of cyclosporin. Experience at a Clinical Pharmacology Service

BACKGROUND: A study on cyclosporine A (CyA) monitoring in the January 1992-December 1995 period is reported. The aim of this work was to give epidemiological data on the use of CyA, to verify the progressive increase of CyA determinations and to evaluate the use in other diseases as well as to compare the different technics of CyA assay in blood samples, to stress the timing of blood samples and to underline the CyA monitoring importance. METHODS: The CyA dosage was evaluated by fluorescence polarization immunoassay (FPIA) and high-performance liquid chromatography (HPLC). RESULTS: The study showed that 70% of CyA determinations come from patients undergone to renal, bone marrow and liver transplantations; the remaining 30% was associated to other diseases (psoriasis, uveitis, diabetes, rheumatoid arthritis). CONCLUSIONS: The results obtained showed a progressive and constant increase of CyA determinations. Moreover, the use of drug was increased in autoimmune diseases. It is stressed that CyA monitoring in blood samples is essential to optimize the therapeutic efficacy of drug and minimizing its toxicity.