Background Biologic drugs have demonstrated efficacy and safety in the treatment of psoriasis. Frequently, label doses tend to be reduced in clinical practice when a sustained response has been reached.

Purpose To assess the proposals of a committee for psoriasis according to drug serum levels and symptoms.

Material and methods A retrospective study of patients with psoriasis and etanercept, adalimumab or infliximab screened by a multidisciplinary committee for psoriasis from January 2016 to August 2017 was developed. The multidisciplinary committee based its proposal on drug serum level and symptoms of psoriasis, and the maintenance, suspension/change or optimised doses of drug. The etanercept serum level was (2–7 µg/ml), adalimumab (5–12 µg/ml) and infliximab (3–10 µg/ml).

Results Ninety-eight patients with psoriasis were included: 44 patients with etanercept of whom 22 were out of range (one over range and 21 below the range). Of the 22 patients within range: five maintained, one suspended/changed and 16 optimised the drug. Of the other 22 patients out of range: 12 maintained, eight suspended/changed and two optimised the drug. Thirty-five patients with adalimumab, of whom 21 were out of range (all below the range). Of the 14 patients within range: six maintained, one suspended/changed and seven optimised the drug. Of the other 21 patients out of range: nine maintained, nine suspended/changed and three optimised the drug. Nineteen patients with infliximab, of whom 12 were out of range (two over range and 10 below the range). Of the seven patients within range, all maintained the drug. Of the other 12 patients out of range: four maintained, six suspended/changed and two optimised the drug.

Conclusion The proposals of the committee were not always strictly correlated with drug serum levels but clinic evolution influences its decision.

Possession of the drug serum levels is one more tool in helping find the best treatment for the patient, but it is also necessary to look for other new tools.

No conflict of interest