Objective: The aim of this study was to assess the safety of the most frequently used biologic disease-modifying antirheumatic drugs in  rheumatoid arthritis patients in clinical practice. Method: A retrospective longitudinal observational study was performed. Clinical information was obtained from the electronic health records of patients diagnosed and treated for rheumatoid arthritis, who had received at least one biologic disease-modifying antirheumatic drug  dispensed between 2001 and 2013 from a third-level Hospital pharmacy. Adverse reactions during biologic disease-modifying antirheumatic  drugs treatments were analysed, as well as the reasons for treatment  discontinuation. A disproportionality analysis (odds ratio with 95% confidence interval) was performed to compare adverse drug reactions related  o different system organ classes, the period between the drug start date and  the reaction start date (latency period), and previous knowledge of the adverse reactions.

Results: In total, 210 patients were included in the analysis (73% women, median age 47 years), with 399 prescriptions for biologic  diseasemodifying antirheumatic drugs and 1,515 adverse reactions potentially  related to them. The increased frequency of adverse reactions for  each system organ class related to each biologic disease-modifying  antirheumatic drug was as follows: general disorders and administration site disturbances with infliximab (2.3 [1.3-4.0]), infections (1.6 [1.3-2.1]) and immune system reactions with etanercept (4.2 [1.2-14.6]), hepatobiliary  disorders with adalimumab (2.1 [1.2-3.6]), ophthalmic adverse  reactions  (1.9 [1.2-3.1]) and cardiac disorders (2.9 [1.0-8.4]) with rituximab,  and blood and lymphatic system disorders with tocilizumab (2.9 [1.8-4.7])  and abatacept (3.0 [1.6-5.8)]. The mean latency period was 5 to 33 months.  Most adverse reactions were related to adalimumab (93.6%; P < 0.01),  whereas the fewest adverse reactions were related to tocilizumab (55.2%; P <  0.01). Most treatment withdrawals related to adverse reactions were identified  during the first year of biologic disease-modifying antirheumatic drugs  treatment.

Conclusions: Tumour necrosis factor α inhibitors were associated with general  disorders and administration site disturbances, infections and immune system reactions, and hepatobiliary abormalities, whereas  ontumour necrosis factor α inhibitors were associated with cardiac disorders as  well as blood and lymphatic system disorders. Treatment  ithdrawals mainly occurred during the first year of treatment. Most of the  adverse reactions have been previously described.