Background Ustekinumab is a fully human IgG1κ monoclonal antibody against interleukin 12 and 23 indicated for the treatment of moderate to severe plaque psoriasis in adults who have failed to respond to previous treatment. The recommended posology is an initial dose of 45 mg (90 mg with a body weight >100 Kg) subcutaneously, followed by the same dose 4 weeks later, and then every 12 weeks thereafter.

Purpose To analyse the use of ustekinumab in our hospital since its launch.

Materials and Methods Retrospective longitudinal study of all the patients with psoriasis treated with ustekinumab since its launch in January 2009 in a tertiary hospital. Data was obtained from the records of outpatients who get their medicines from the hospital pharmacy, and before February 2010, we used records of ustekinumab prescriptions that required validation from the inspection service.

Main outcome measures: gender, age, dose, time in treatment, previous use of a biological antiTNF, changes in frequency of administration, induction posology at the beginning.

Statistics: Descriptive analysis of qualitative and quantitative data, unpaired t-test with SPSS 17.0.

Results The review consisted of 57 patients (56.1% men) with a mean age of 52 (SD 12.9) for men and 43 years old (SD 19.2) for women (P = 0.05). In 9 patients (one woman) the dose used was 90 mg. In 35 cases (61.4%) the patients received a previous treatment with biological antiTNF and in 12 patients the treatment started every 12 weeks directly (without induction). The physicians changed the frequency in 10 patients (17.5%): 5 with doses every 16–20 weeks and 5 with interruptions with a mean of 7.6 months.

Currently 11 patients have stopped the treatment and the average time of treatment is 19.3 months (SD 9.9).

Conclusions Ustekinumab was the first-line biological treatment in 38.6% of patients.

A significant number of patients used 90 mg, and it could be interesting to evaluate whether a 45 mg dose would be sufficiently effective to reduce the cost.

No conflict of interest.