Neoral conversion in stable thoracic transplant patients leads to dose reduction

Methods for clinical monitoring of cyclosporin in transplant patients

Cyclosporin was introduced into clinical practice in the early 1980s and has since been shown to prolong survival for transplant recipients. Because cyclosporin is a narrow therapeutic index drug and there are significant consequences associated with 'subtherapeutic' and 'supratherapeutic' concentrations, cyclosporin therapy is monitored as part of routine patient follow-up. However, the optimal method for the therapeutic drug monitoring of cyclosporin has yet to be defined. Currently, the most common method involves monitoring pre-dose trough concentrations, but this method is less than ideal. Other methods of monitoring cyclosporin therapy include monitoring the area under the concentration-time curve, limited sampling strategies, monitoring of single concentrations other than troughs and pharmacodynamic monitoring. Bayesian forecasting has been used successfully in clinical practice with other drugs with narrow therapeutic indices. However, few studies are available regarding Bayesian forecasting and cyclosporin. Existing studies are preliminary in nature and involve the old Sandimmun formulation rather than the Neoral formulation. Although these methods show promise, they have not gained widespread acceptance. This is because of their impracticality and the lack of prospective studies comparing other monitoring methods with trough concentration monitoring. Further comparative studies evaluating the impact of the specific monitoring method on definite patient outcomes are warranted.

Renal function one year after switching from Sandimmun to Neoral

BACKGROUND

The replacement of Sandimmun by Neoral in 1995 was thought to cause subsequent renal function deterioration due to the better bioavailability of the new drug. We prospectively analyzed the effect of a dose-to-dose drug replacement on renal function over 12 months.

METHODS AND RESULTS

The renal function of 47 consecutive heart transplanted patients was prospectively evaluated before (T0), at 1 (T1), 3 (T3), and 12 (T12) months after drug replacement. Mean serum creatinine was not significantly different at T0 and T12 (142 +/- 55 and 154 +/- 60 micromol/L, p = 0.1). We were able to reduce cyclosporine total and weight-indexed doses by, respectively, 11% and 14% between T0 and T12 (274 +/- 86 to 244 +/- 72 mg/d, p = 0.0003; and 3.7 +/- 1.4 to 3.2 +/- 1.2 mg/kg/d, respectively, p = 0.0005).

CONCLUSIONS

This study demonstrates that the dose-to-dose replacement of Sandimmun by Neoral is feasible, with no direct influence on renal function over a 1-yr follow-up.