Incidence of bleeding events in patients on concomitant tyrosine kinase inhibitors and selective serotonin reuptake inhibitors

Introduction In this study, we aim to determine the risk of bleeding or thrombosis with concurrent use of tyrosine kinase inhibitors (TKIs) used to treat CML, and serotonin reuptake inhibitors (SSRIs). Methods We conducted a retrospective cohort study of patients with CP-CML cared for at Massachusetts General Hospital (MGH) between April 2016 to February 2021. Participants were included if diagnosed with CP-CML and began TKI treatment (imatinib, dasatinib, nilotinib, bosutinib, or ponatinib) after April 2016. Results One hundred patients were evaluated, eighty of whom were taking TKIs only (median age 55, 40% female), and twenty were taking TKI and SSRI concomitantly (median age 53.5, 55% female). Baseline demographics between these groups were similar across all variables. Patients in the TKI only group had 9 bleeding events and 3 thrombotic events. Patients in the combination group had 6 bleeding events and 1 thrombotic event. There was no difference between overall rates of major bleeding (4% v. 10%, p = 0.26) or thrombotic events (4% v. 5%, p = 1). However, patients in the combination group were more likely to have major intracranial bleeding events (0% v. 10%, p = 0.04), and there was a trend to significance for minor bleeding events (7.5% v. 20%, p = 0.11). Conclusions Concomitant use of TKIs and SSRIs does not appear to increase the total risk of bleeding or thrombotic events compared to patients on TKIs only. However, concomitant use of TKIs and SSRIs may increase risk of intracranial bleeding. Further work is needed to fully assess this risk.