Abstract
Background Polypharmacy, including use of inhibitors of CYP3A4 and P-glycoprotein (P-gp), is common in patients with venous thromboembolism (VTE) and is associated with increased bleeding. Methods In 8246 patients included in the EINSTEIN-VTE studies for acute VTE, we evaluated the effect of polypharmacy on bleeding and on the relative differences between rivaroxaban and enoxaparin/vitamin K antagonist (VKA). We assessed the incidence of clinically relevant bleeding (major and clinically relevant nonmajor bleeding) by number of comedications (none, 1-3, >= 4) at baseline, and by use of CYP3A4 and/or P-gp inhibitors. Interaction between rivaroxaban versus enoxaparin/VKA and comedication was assessed by Cox regression analysis with p(interaction) estimates. Results With increasing number of comedications, the incidence of clinically relevant bleeding rose from 5.7% to 13.3% in rivaroxaban recipients and from 9.1% to 11.1% in enoxaparin/VKA recipients. Whereas rivaroxaban was associated with a reduced bleeding risk compared with enoxaparin/VKA in patients without comedication (hazard ratio [HR] 0.6, 95% confidence interval [CI] 0.4-0.9), the risk was similar in patients with >= 4 comedications (HR 1.2, 95% CI 0.97-1.5, p(interaction) .002). Use of CYP3A4 and/or P-gp inhibitors was associated with a doubled bleeding risk compared with no use, without a difference between rivaroxaban and enoxaparin/VKA. Conclusion We conclude that fixed-dose rivaroxaban as compared with enoxaparin followed by dose-adjusted VKA is not associated with an increased bleeding risk in patients with VTE administered polypharmacy in general and CYP3A4 and/or P-gp inhibitors specifically. This implies that the observed increased bleeding risks with polypharmacy and use of CYP3A4 and/or P-gp inhibitors are likely explained by comorbidities and frailty, and not by pharmacokinetic interactions.
Original language | English |
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Pages (from-to) | 1376-1384 |
Number of pages | 9 |
Journal | Journal of Thrombosis and Haemostasis |
Volume | 20 |
Issue number | 6 |
Early online date | 7 Mar 2022 |
DOIs | |
Publication status | Published - Jun 2022 |
Keywords
- ORAL RIVAROXABAN
- coumarins
- hemorrhage
- polypharmacy
- rivaroxaban
- venous thromboembolism