title: Therapeutic drug monitoring of cyclosporine microemulsion in patients with corticosteroid-resistant systemic lupus erythematosus.
abstract: OBJECTIVE
  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.
authors.affiliation: a Department of Internal Medicine (I) , Osaka Medical College , Takatsuki, Osaka , Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Wada
authors.forename: Takuya
authors.initials: T
authors.lastname: Kotani
authors.forename: Tohru
authors.initials: T
authors.lastname: Takeuchi
authors.forename: Reiko
authors.initials: R
authors.lastname: Wakura
authors.forename: Daisuke
authors.initials: D
authors.lastname: Wakura
authors.forename: Shigeki
authors.initials: S
authors.lastname: Makino
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hanafusa
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D016572:Cyclosporine / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use*; D008180:Lupus Erythematosus, Systemic / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D007166:Immunosuppressive Agents; D016572:Cyclosporine
keywords: C2 monitoring; Cyclosporine; Systemic lupus erythematosus