Cyclosporine (ciclosporin) is a drug that decreases immune system response. It is used alone or in combination with other drugs to prevent transplant rejection in transplant programs. Cyclosporine (ciclosporin) is also used to treat certain cases of severe psoriasis or rheumatoid arthritis as well as nephrotic syndrome. The minimum blood level of cyclosporine (ciclosporin) is usually measured 12 hours after the last dose or before the next dose is taken. Results are expressed in nanograms of cyclosporine (ciclosporin) per millilitre of whole blood (ng/mL). The technique used is liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS).
Therapeutic levels of the drug vary depending on the type of organ transplanted and the length of time since the transplant. For monitoring kidney transplant rejection, most individuals respond adequately and with minimal side effects to a minimum (pre-dose) cyclosporine (ciclosporin) level of 80 to 320 ng/mL. There is a risk of rejection when levels are below 80 ng/mL, and a risk of toxicity (especially to the kidneys) when levels are above 320 ng/mL. Measured rates vary depending on the testing method. It is therefore important for cyclosporine (ciclosporin) levels to be monitored always using the same technique.