Objectives: We retrospectively examined how the cyclosporine-A (CSA) microemulsion administration mode affected blood CSA levels, as well as how the dose and blood levels of CSA affected its therapeutic effect against systemic lupus erythematosus (SLE).
Methods: We calculated the area under the blood concentration time curve (AUC) of CSA in 16 patients with corticosteroid-resistant SLE, and analyzed its correlation with CSA levels at the blood sampling time points to investigate the optimum monitoring and dosing regimen.
Results: The blood CSA level peaked at 2 h after administration (C2) in all patients. AUC0-6, which most markedly reflects the immunosuppressive effect, significantly correlated with C2 (R2 = 0.905), but not with the trough (C0). In concentration/dose ratio (C/D) of CSA, C2/D level was significantly higher when administered once daily before breakfast than when administered in the divided dose after meals (R2 = 0.355, P = 0.015), but not C0/D. During the 6-month follow-up, the CSA C2 tended to correlate with improvement in SLE disease activity index 2000 (R2 = 0.633, P = 0.067).
Conclusions: The treatment with a single dose of CSA before breakfast, followed by monitoring of C2, may be useful for improving the therapeutic effect in patients with corticosteroid-resistant SLE.
Keywords: C2 monitoring; Cyclosporine; Systemic lupus erythematosus.