A Limited Sampling Strategy for the Estimation of 12-Hour SangCya and Neoral AUCs in Renal Transplant Recipients

Neoral and SangCya are new cyclosporine formulations with more consistent pharmacokinetic profiles than the older formulation of cyclosporine, Sandimmune. Limited sampling strategies have been derived to estimate the full area under the curve (AUC) for both Neoral and Sandimmune. In addition, no limited sampling strategy has been derived for SangCya, and no rigorous prospective testing has been done on any of these formulas. The authors studied 32 renal transplant patients who received Neoral and then SangCya during a formulation conversion study. Full AUCs were drawn on all patients (twice while on Neoral, once while on SangCya). Abbreviated formulas were derived using linear regression models and then tested for the prediction error. The authors found that several abbreviated formulas offer excellent estimations of the full AUC for both SangCya and Neoral. The generated formulas worked equally well with either formulation. In addition, the authors found that limited sampling strategies using a 1.5‐hour sample may predict a full AUC more accurately than those that use a 2‐hour sample. The use of these abbreviated formulas allows for a convenient and accurate estimate of CsA exposure.