Intravenous Cetirizine vs Intravenous Diphenhydramine for the Prevention of Hypersensitivity Infusion Reactions: Results of an Exploratory Phase 2 Study

Effect of Switching the Histamine-1 Receptor Antagonist Clemastine to Cetirizine in Paclitaxel Premedication Regimens: The H1-Switch Study

PURPOSE

Premedication, including a histamine-1 receptor (H1) antagonist, is recommended to all patients treated with paclitaxel chemotherapy to reduce the incidence of hypersensitivity reactions (HSRs). However, the scientific basis for this premedication is not robust, which provides opportunities for optimization. Substitution of intravenously administered first-generation H1 antagonist for orally administered second-generation H1 antagonist could reduce side effects, and improve efficiency and sustainability. This study investigates the efficacy and safety of substituting intravenous clemastine for oral cetirizine as prophylaxis for paclitaxel-induced HSRs.

METHODS

This single-center, prospective, noninferiority study compares a historic cohort receiving a premedication regimen with intravenous clemastine to a prospective cohort receiving oral cetirizine. Primary end point of the study is HSR grade ≥3. The difference in incidence was calculated together with the 90% CI. We determined that the two-sided 90% CI of HSR grade ≥3 incidence in the oral cetirizine cohort should not be more than 4% higher (ie, the noninferiority margin) compared with the intravenous clemastine cohort.

RESULTS

Two hundred and twelve patients were included in the oral cetirizine cohort (June 2022 and May 2023) and 183 in the intravenous clemastine cohort. HSR grade ≥3 incidence was 1.6% (n = 3) in the intravenous clemastine cohort and 0.5% (n = 1) in the oral cetirizine cohort, resulting in a difference of -1.2% (90% CI, -3.4 to 1.1).

CONCLUSION

Premedication containing oral cetirizine is as safe as premedication containing intravenous clemastine in preventing paclitaxel-induced HSR grade ≥3. These findings could contribute to optimization of care for patients and improve efficiency and sustainability.

Evaluating the efficacy of a premedication regimen including high-dose cetirizine in reduction of hypersensitivity reactions to paclitaxel: A retrospective cohort study

INTRODUCTION

Hypersensitivity reactions (HSR) are a known adverse effect of paclitaxel, occurring in approximately 10% of patients, typically during the first or second infusion of the medication. Corticosteroids, histamine-1 and histamine-2 receptor antagonists are given prior to paclitaxel infusions to reduce the incidence of HSR. There are limited data that suggest administration of cetirizine given prior to a platinum infusion as secondary prophylaxis may reduce HSR rates.

METHODS

The objective of this study was to assess the impact of a novel paclitaxel hypersensitivity prevention protocol including high-dose cetirizine administered 12 and 6 h prior to paclitaxel infusion on the rate of HSR compared to a historical control. The primary objective was the rate of HSR of any grade after the first cycle of paclitaxel. Secondary outcomes included grade of infusion reaction and incidence of severe HSR.

RESULTS

A total of 104 patients were included for analysis in the cetirizine group and 124 in the control group. Hypersensitivity reactions occurred in 37 (16.2%) patients in the overall population, and no statistical difference was observed between groups. (13.46% vs 18.55%; p = 0.23). Numerically more grade 3-4 HSRs occurred in the control group than the treatment group (30.77% vs 69.23; p = 0.51).

CONCLUSIONS

The addition of cetirizine to paclitaxel infusions resulted in numerically lower rates of HSR and a reduction in severity of grade 3-4 HSRs. Future studies with more robust compliance data and a larger patient population would be needed to appropriately assess the efficacy of our novel treatment regimen.

Repurposing of H1-receptor antagonists (levo)cetirizine, (des)loratadine, and fexofenadine as a case study for systematic analysis of trials on clinicaltrials.gov using semi-automated processes with custom-coded software

To gain a comprehensive overview of the landscape of clinical trials for the H1-receptor antagonists (H1R antagonists) cetirizine, levocetirizine, loratadine, desloratadine, and fexofenadine and their potential use cases in drug repurposing (the use of well-known drugs outside the scope of the original medical indication), we analyzed trials from clincialtrials.gov using novel custom-coded software, which itself is also a key emphasis of this paper. To automate data acquisition from clincialtrials.gov via its API, data processing, and storage, we created custom software by leveraging a variety of open-source tools. Data were stored in a relational database and annotated facilitating a specially adapted web application. Through the data analysis, we identified use cases for repurposing and reviewed backgrounds and results in the scientific literature. Even though we found very few trials with published results for repurpose indications, extended literature research revealed some prominent use cases: Cetirizine seems promising in mitigating infusion-associated reactions and is also more effective than placebo in the treatment of androgenetic alopecia. Loratadine may be beneficial in the prophylaxis of G-CSF-related bone pain. In COVID-19, H1R antagonists may be helpful, but placebo-controlled scientific evidence is needed. For asthma, the effect of H1R antagonists only seems to be secondary by alleviating allergy symptoms. Our novel method to find potential use cases for repurposing of H1R antagonists allows for high automation, reduces human error, and was successful in revealing potential areas of interest. The software could be used for similar research questions and analyses in the future.

Comparing the Risk of Infusion-Related Reactions and Tolerability in Patients Given Cetirizine or Diphenhydramine Prior to Ocrelizumab Infusion (PRECEPT)

Background: Ocrelizumab is an effective medication for multiple sclerosis. However, infusion-related reactions (IRRs) are a concern for patients and may lead to discontinuation of ocrelizumab. To minimize IRRs, pre-medications are administered. However, from our experience, these medications, especially diphenhydramine, can cause marked drowsiness. The primary objective of this study was to evaluate whether cetirizine is non-inferior to diphenhydramine in limiting the proportion and severity of reactions from ocrelizumab infusions. Methods: Twenty participants were serially randomized in a 1:1 ratio to receive 10 mg of cetirizine or 25 mg of diphenhydramine orally prior to their first three ocrelizumab infusions. Results: The rate of IRRs in this study was similar across both treatment groups with no increase in the risk of severity, and no grade 3 IRRs. Further, patients receiving cetirizine experienced a reduction in fatigue. While there was not a significant difference in global satisfaction, this score increased over time in the cetirizine arm while it remained unchanged in the diphenhydramine arm. Conclusions: Overall, our results suggest that cetirizine does not increase the risk of infusion-related reactions compared to diphenhydramine.

The Role of Cetirizine in the Changing Landscape of IV Antihistamines: A Narrative Review

Since 1955, the only available H1 antihistamines for intravenous administration have been first-generation formulations and, of those, only intravenously administered (IV) diphenhydramine is still approved in the USA. Orally administered cetirizine hydrochloride, a second-generation H1 antihistamine, has been safely used over-the-counter for many years. In 2019, IV cetirizine was approved for the treatment of acute urticaria. In light of this approval, this narrative review discusses the changing landscape of IV antihistamines for the treatment of histamine-mediated conditions. Specifically, IV antihistamines will be discussed as a treatment option for acute urticaria and angioedema, as premedication to prevent infusion reactions related to anticancer agents and other biologics, and as an adjunct treatment for anaphylaxis and other allergic reactions. Before the development of IV cetirizine, randomized controlled trials of IV antihistamines for these indications were lacking. Three randomized controlled trials have been conducted with IV cetirizine versus IV diphenhydramine in the ambulatory care setting. A phase 3 trial of IV cetirizine 10 mg versus IV diphenhydramine 50 mg was conducted in 262 adults who presented to the urgent care/emergency department with acute urticaria requiring antihistamines. For the primary efficacy endpoint, defined as change from baseline in a 2-h patient-rated pruritus score, non-inferiority of IV cetirizine to IV diphenhydramine was demonstrated (score - 1.6 vs - 1.5, respectively; 95% CI - 0.1, 0.3). Compared with IV diphenhydramine, IV cetirizine demonstrated fewer adverse effects including less sedation, a significantly shorter length of stay in the treatment center, and fewer returns to the treatment center at 24 and 48 h. Similar findings were demonstrated in another phase 2 acute urticaria trial and in a phase 2 trial assessing IV cetirizine for pretreatment for infusion reactions in the oncology/immunology setting. IV cetirizine is associated with similar patient outcomes, fewer adverse effects, and increased treatment center efficiency than IV diphenhydramine.