The clinical benefits of cyclosporine C2-level monitoring: a systematic review.

BACKGROUND: Monitoring of cyclosporine microemulsion (Neoral) using 2-hour postdose (C2) levels is alleged to improve clinical outcomes, but the efficacy of this strategy is uncertain.
METHODS: A systematic literature search was performed for trials directly comparing patients monitored with C2 levels with those monitored by trough (C0) levels. Primary outcomes assessed were renal function and acute rejection.
RESULTS: A total of 29 studies met the inclusion criteria. Only 10 of these were randomized controlled trials. Overall quality was poor and this precluded meta-analysis. The most consistent finding in de novo renal, hepatic, and cardiac transplant recipients is a higher mean cyclosporine dose in the early postoperative period in C2 monitored patients. There is no clear evidence that this leads to impaired renal function. In the majority of studies, the monitoring strategy had no significant effect on the rate of acute rejection. In stable transplant recipients, the majority of studies show a reduction in mean cyclosporine dose with adoption of C2 monitoring. No obvious clinical benefit was derived from this reduction in dose.
CONCLUSION: In de novo transplant patients, there is little evidence from prospective studies to support the theoretical benefits of C2 monitoring. Potential dose reductions in stable patients may reduce costs, but no short-term clinical benefit is seen. Quality of studies in this area is poor, and the practical limitations of C2 monitoring mean that further evidence is required before a strategy for the administration of cyclosporine based on C2 levels can be recommended.