Sex differences in adverse drug reactions from Adalimumab and etanercept in patients with inflammatory rheumatic diseases

Background: We examine sex differences in relation to the nature, frequency, and burden of patient-reported adverse drug reactions (ADRs) in patients with inflammatory rheumatic diseases. Research design and methods: Rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis patients using etanercept or adalimumab from the Dutch Biologic Monitor were sent bimonthly questionnaires concerning experienced ADRs. Sex differences in the proportion and nature of reported ADRs were assessed. Additionally, 5-point Likert-type scales reported for the burden of ADRs, were compared between sexes. Results: In total 748 consecutive patients were included (59% female). From the women 55% reported ≥1 ADR, which was significantly higher than 38% of the men that reported ≥1 ADR (p < 0.001). A total of 882 ADRs were reported comprising 264 distinct ADRs. The nature of the reported ADRs differed significantly between both sexes (p = 0.02). Women in particular reported more injection site reactions than men. The burden of ADRs was similar between sexes. Conclusions: Sex differences in the frequency and nature of ADRs, but not in ADR burden, exist during treatment with adalimumab and etanercept in patients with inflammatory rheumatic diseases. This should be taken into consideration when investigating and reporting results on ADRs and when counseling patients in daily clinical practice.