SAT0607 Drugs used off label in a rheumatology service of a terciary hospital

Background The use of drugs off-label (DOL) is not uncommon in Rheumatology daily clinical practice for the treatment of patients with immune-mediated inflammatory diseases (IMID). Objectives To analyse the use of DOL requested by the Rheumatology Service. Methods We reviewed the medical records of all patients registered in the DOL database of the Hospital Pharmacy Service between July 2009 and March 2017. The following variables were collected: date of approval and start of the drug, physician, disease, reason for indication, sex and age of the patients, response to treatment according to the global assessment of the responsible physician, date and reason of withdrawal. A descriptive study of the variables collected through STATA 12 is carried out. Results 225 DOL were requested for a total of 174 patients. Women were 78.7%, with an average age of 56.5 years (sd 1.15). In most patients (77%) a single drug was requested. In 37 patients were requested between two (16.4%) and seven drugs (0.5%). The indications of the DOL in our database were: connective tissue diseases (CTD: 46.6%), vasculitis (23%), rheumatoid arthritis (RA: 5.2%) and spondyloarthritis (SPA:8%). Other diseases (17.2%) are included in two heterogeneous groups classified according to their ethiology (autoimmune (8.6%) or not (8.6%). 39.5% of the drugs requested were conventional synthetic DMARDs (csDMARDs), 38.2% biological DMARDs (bDMARDs), 7.5% were antivirals, 2.6% vasodilators and 12% other drugs. Conventional synthetic DMASDs (csDMARDs) represented 39.5% of request, biological DMARDs (bDMARDs) 38.2%, antiviral drugs 7.5%, vasodilator drugs 2.6% and other drugs 12%. Tables 1 and 2 show csDMARDs and bDMARDs respectively, according to the indication. The effectiveness of the DOL was variable, ranging between 0% and 76.5%. The most effective were antiviral drugs, used to treat viral infections in immunosuppressed patients (76.5%), tocilizumab (72.2%) and rituximab (61.1%). By contrast, the least effective were anakinra (0%) and TNF blockers (31.8%). The cs DMARDs group had an effectiveness of 53.9% (Mycophenolate stands out with 75% effectiveness). The disease groups that responded best to DOL therapy were connective tissue and vasculitis, with 58% and 53.7% of effectiveness. Conclusions Rheumatic diseases for which DOL is most commonly requested are connective tissue and vasculitis, as a consequence of the absence of specific indications for these pathologies. In our experience, rituximab is a good option in the treatment of connective tissue diseases, which contrasts with the results of some clinical trials. Tocilizumab is a good therapeutic option in the treatment of vasculitis, a group that includes Giant Cell Arteritis, as recently confirmed with its approval for this indication. Disclosure of Interest None declared