Long-term treatment of psoriasis with cyclosporin A--side-effects, minimal effective dose and cyclosporin blood levels.

Fourteen patients with psoriasis received long-term treatment with cyclosporin (CsA). Among patients there was great variability in the minimal effective CsA dose. In most patients long-term treatment was limited due to dose reductions made necessary because of side-effects. The therapeutic window for CsA seems small. CsA blood levels associated with side-effects and with the minimal effective dose are in the same range and correlation between CsA blood levels and effectiveness in psoriasis is weak. Therefore, in CsA therapy for psoriasis, without concomitant medication which may influence CsA blood levels, the measurement of CsA blood levels is not necessarily helpful in optimizing therapy or preventing side-effects.