Background Rituximab is a monoclonal antibody indicated in Spain in adults with non-Hodgkin’s lymphoma, chronic lymphatic leukaemia, rheumatoid arthritis and granulomatosis with polyangiitis and microscopic polyangiitis.

Purpose To evaluate the use of rituximab in a district hospital in off-label conditions which did not respond to corticosteroids or immunosuppressants treatment.

Material and methods We carried out a retrospective observational study of the use of rituximab off-label from its inclusion in the pharmacotherapeutic guide of the hospital in 2009 until July 2018.

Data collected: number of patients, sex, age, diagnosis, previous treatment with rituximab, concomitant treatment with rituximab, treatment schemes and adverse effects 6 months after the start of treatment. Digital clinical history and external consultations application were used. Statistical analysis was performed with SPSS version 24.

Results Number of patients: 21. Sex: 11 (52.4%) males. Mean Age: 53.3 (21–80). Diagnostic groups: six patients (28.6%) developed glomerulonephritis, five (23.8%) lupus, five (23.8%) vasculitis for cryoglobulins and ANCA positive, three (14.3%) myositis and two (9.5%) pemphigus. Treatment prior to rituximab: all patients were treated with prednisone, 11 (52.4%) with mycophenolate mofetil, 10 (47.6%) with azathioprine, 10 (47.6%) with cyclosporine A, six (28.6%) with hydroxychloroquine, three (14.3%) methotrexate, two (9.5%) with tacrolimus, one (4.8%) with immunoglobulins and one (4.8%) with monoclonal antibodies. Concomitant treatment with rituximab: all patients had been treated with prednisone, five (23.8%) with hydroxychloroquine, five (23.8%) with azathioprine, four (19%) with mycophenolate mofetil and two (9.5%) with tacrolimus. Treatment schemes: eight (38.1%) patients received 15 day cycles with a fixed dose of 1000 mg on days 1 and 15. Ten patients (47.6%) with 500 mg weekly for 4 weeks and three patients (14.3%) received doses of 875 mg/m² weekly for 4 weeks. Adverse reactions: 11 patients (52.4%) developed cytopaenia. The most frequent cytopaenia was anaemia: five patients 45.4%. Seven (33.3%) patients developed pneumonia or sepsis that required hospital admission. A case of atrial fibrillation was recorded. No reactions related to the perfusion of rituximab were recorded.

Conclusion The use of rituximab off-label has increased in recent years. It is therefore necessary to develop protocols to unify the criteria for use, evaluating its effectiveness and safety profile to increase the quality of care.

References and/or acknowledgements No conflict of interest.