Cyclosporine monitoring in autoimmune and other diseases

Cyclosporine (CsA) is being increasingly used for the treatment of disorders other than transplantation. In contrast to transplant recipients, most of these patients can have CsA therapy discontinued without life-threatening consequences, and the dose of CsA can therefore be restricted in order to limit the incidence and severity of toxicity, including nephrotoxicity. The utility of either CsA blood levels or pharmacokinetic profiling to ensure adequacy of therapy or to prevent incipient as well as overt toxicity has not been confirmed in this group of patients, and prevention of nephrotoxicity usually depends on limiting the dose of CsA and careful assessment of renal function. Frequent measurement of CsA levels beyond the initiation period in patients with autoimmune and other nontransplant diseases cannot be currently justified, and should be reserved for those situations where drug interactions, unexpected toxicity or the possibility of inadequate therapy is likely.