Suitable Whole Blood Levels 2 Hours After Neoral in Liver Transplant Patients: Experiences at a Single Center

Abstract Whole blood levels 2 hours after Neoral (C 2 ) administration were observed to correlate better with area under the curve (AUC 0–4 ) than trough levels (C 0 ), suggesting that C 2 may be the best single time point predictor of Neoral absorption. Owing to concerns about drug toxicity due to excessive immunosuppression, C 2 adjustments to target blood levels may represent an advance. The present study measured C 2 and levels to determine which correlated more closely with AUC 0–4 . Methods Between August 2003 and July 2004, 40 adult liver transplantations were performed in our center. All patients received Neoral twice daily. They were maintained at a C 0 level of about 200 ng/mL. C 0 levels were measured daily. C 2 levels were estimated on postoperative days 3, 5, 7, 14, and 28. AUC 0–4 performed on postoperative days 3, 7, and 28 was calculated using the trapezoidal rule. Results The mean AUC 0–4 , C 0 , C 1 , C 2 , C 3 , and C 4 were 1100.3 ± 484.8 ng/mL, 197.1 ± 84.7 ng/mL, 240.7 ± 166.2 ng/mL, 307.8 ± 162.6 ng/mL, 302.8 ± 138.9 ng/mL, and 300.3 ± 142.8 ng/mL, respectively. C 2 correlated with AUC 0–4 ( R 2 = 0.868: P 0 ( R 2 = 0.245: P 1 ( R 2 = 0.604: P 4 ( R 2 = 0.583: P Conclusions Neoral dose monitoring according to a mean C 2 range of 307.8 ± 162.6 ng/mL correlated better with AUC 0–4 . Further studies are required to determine suitable C 2 levels in liver transplant patients.