• cyclosporin;
  • fixed-dose;
  • low-dosage;
  • psoriasis;
  • safety


Cyclosporin is a second-line modality for the treatment of psoriasis. The long-term efficacy of cyclosporin and potential adverse side-effects, however, are a concern to patients. Therefore, a cyclosporin microemulsion (Neoral), which is steadily absorbed at an ultra-low dosage (1–2 mg/kg per day) or low dosage (2–3 mg/kg per day), is currently recommended. The dose must be calculated based on patient bodyweight and the blood concentration monitored regularly, which is time-consuming. Furthermore, the concentration is related to the safety profile, but not to efficacy. We examined whether a fixed-dose cyclosporin microemulsion (100 mg/day) is effective for treating psoriasis. Enrolled patients (n = 40) were given either 100 mg cyclosporin emulsion once daily (group A) or 50 mg twice daily (group B), regardless of patient weight and condition, before meals in a randomized controlled study. Patient bodyweight ranged 50–80 kg. We assessed the serum cyclosporin concentration 1 h after administrating the medicine (C1 score), Psoriasis Area and Severity Index (PASI) score, quality of life, and the results of regular blood examinations. The improvement rate was 69.4 ± 4.8% in group A and 73.4 ± 4.3% in group B. PASI-50 was achieved by 82% in group A and 84% in group B. At 6 weeks, the number of patients with PASI-50 was significantly higher in group A than in group B. PASI-75 and -90 were also achieved in both groups with no significant difference between groups. Administration of a fixed-dose cyclosporin microemulsion (100 mg/day) is practical for second-line psoriasis treatment.