Background: Cyclosporine (INN, ciclosporin) increases the systemic exposure of all statins. Therefore rosuvastatin pharmacokinetic parameters were assessed in an open-label trial involving stable heart transplant recipients (> or =6 months after transplant) on an antirejection regimen including cyclosporine. Rosuvastatin has been shown to be a substrate for the human liver transporter organic anion transporting polypeptide C (OATP-C). Inhibition of this transporter could increase plasma concentrations of rosuvastatin. Therefore the effect of cyclosporine on rosuvastatin uptake by cells expressing OATP-C was also examined.
Methods: Ten subjects were assessed while taking 10 mg rosuvastatin for 10 days; 5 of these were then assessed while taking 20 mg rosuvastatin for 10 days. Rosuvastatin steady-state area under the plasma concentration-time curve from time 0 to 24 hours [AUC(0-24)] and maximum observed plasma concentration (Cmax) were compared with values in controls (historical data from 21 healthy volunteers taking 10 mg rosuvastatin). Rosuvastatin uptake by OATP-C-transfected Xenopus oocytes was also studied by use of radiolabeled rosuvastatin with and without cyclosporine.
Results: In transplant recipients taking 10 mg rosuvastatin, geometric mean values and percent coefficient of variation for steady-state AUC(0-24) and Cmax were 284 ng. h/mL (31.3%) and 48.7 ng/mL (47.2%), respectively. In controls, these values were 40.1 ng. h/mL (39.4%) and 4.58 ng/mL (46.9%), respectively. Compared with control values, AUC(0-24) and Cmax were increased 7.1-fold and 10.6-fold, respectively, in transplant recipients. In transplant recipients taking 20 mg rosuvastatin, these parameters increased less than dose-proportionally. Rosuvastatin had no effect on cyclosporine blood concentrations. The in vitro results demonstrate that rosuvastatin is a good substrate for OATP-C-mediated hepatic uptake (association constant, 8.5 +/- 1.1 micromol/L) and that cyclosporine is an effective inhibitor of this process (50% inhibition constant, 2.2 +/- 0.4 micromol/L when the rosuvastatin concentration was 5 micromol/L).
Conclusions: Rosuvastatin exposure was significantly increased in transplant recipients on an antirejection regimen including cyclosporine. Cyclosporine inhibition of OATP-C-mediated rosuvastatin hepatic uptake may be the mechanism of the drug-drug interaction. Coadministration of rosuvastatin with cyclosporine needs to be undertaken with caution.