Comparative inhibitory effects of bepotastine and diphenhydramine on rituximab-induced infusion reactions

Purpose Infusion-related reaction (IRR) is a common adverse event induced by rituximab. Although first-generation histamine 1 receptor antagonists (H1RAs) are commonly used to prevent IRR, evidence on IRR suppression by the second-generation H1RA bepotastine is scarce. In this study, we assessed the inhibitory effects of bepotastine on rituximab-induced IRR and compared them with those of the first-generation H1RA diphenhydramine.
Methods We retrospectively evaluated IRR incidence in patients with B-cell non-Hodgkin lymphoma who received their first dose of rituximab.
Results The incidence of any grade IRR was 9.8% in the bepotastine group (n = 92), which was significantly lower than the 30.2% rate in the diphenhydramine group (n = 96; p < 0.001). The incidence of grade 2 or higher IRR was similar between the two groups (6.5% vs. 12.5%; p = 0.16). Multivariable logistic regression analysis revealed that the risk of any grade IRR incidence was higher in patients with B symptoms and bulky disease. Premedication with bepotastine was an independent factor in reducing the risk of any grade IRR incidence (odds ratio = 0.19, 95% confidence interval: 0.08–0.47).
Conclusion Bepotastine may be more effective than diphenhydramine in reducing the incidence of rituximab-induced IRR, particularly low-grade reactions.

The version of record of this article, first published in International Journal of Hematology, is available online at Publisher’s website: http://dx.doi.org/10.1007/s12185-025-03990-6