PS-008 The effect of disease-modifying antirheumatic drugs on the suspension of biologic al treatment due to adverse effects

Background Anti-TNF drugs (AD)s have been a major advance in the control of chronic rheumatic diseases, however they sometime have important adverse drug effects (ADEs). Purpose To assess the frequency of AD and disease-modifying antirheumatic drug(DMARD) combinations leading to withdrawal of biological treatment (BT) due to ADEs. Material and methods Observational study in a tertiary hospital (1,350 beds). Outpatients on BT followed in a rheumatic disease unit were included. We evaluated patients who had been prescribed infliximab, etanerceptor adalimumabconcomitantly with DMARDs (between November 1999 and March 2013). The primary end point was BT withdrawal due to ADEs. Results 444 patients out of 531 took DMARDs at the same time as ADs. 52 (11.7%) discontinuedtreatment due to ADEs as did 10 patients receiving anti-TNF monotherapy (11.5%) (OR = 0.27; p > 0.05). 160 patients took leflunomide, 28 of them (17.5%) discontinuedAD due to ADEs. This risk of discontinuationwas significantly higher than in patients receiving other concomitant DMARDs (OR = 1.984; p 0.05). The frequency of AD withdrawal was similar when comparing patients on monotherapy versus polytherapy (anti-TNF and DMARDs) regardless of drug or diagnoses. Only leflunomideshowed significantly higher ADEs which led to BT interruption (OR = 1.984; p 0.05). There was an increase in discontinuationswith each additional number of concomitant DMARDs up to a maximum of three. Conclusion Association of anti-TNF with different DMARDs did not modify the risk of BT withdrawal as a consequence of ADEs. As a DMARD was added to any AD, the number of its discontinuationsincreased. The addition of BT treatment concomitantly with leflunomidesignificantly increased the risk of anti-TNF discontinuationdue to ADEs, while patients taking methotrexate with BT were less likely to develop ADEs. References and/or acknowledgements Rheumatology Department No conflict of interest.