Bilastine in the treatment of allergic rhinitis – meta-analysis shows advantage of lower somnolence

Oral antihistamines

Bilastine is a non-sedative drug of the 2nd generation of oral antihistamines (OAH) with a high specific affinity for the H₁ histamine receptor, where it acts as an inverse agonist. The binding of bilastine to the receptor inhibits histamine activities. The treatment with the 1st generation OAH is accompanied by increased somnolence. The 2nd generation OAH have the advantage of reduced absorption through the blood-brain barrier, resulting in minimal penetration into the brain and reduced side effects on the central nervous system.

Analyzed studies

The authors created a detailed and extensive review of the literature on the efficacy and safety of bilastine in the treatment of AR compared to placebo and other pharmacotherapy modalities. They searched databases such as the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Science Direct, and Google Scholar for randomized controlled trials with patients diagnosed with AR, objectively determined by clinical physicians, with a minimum follow-up period of 2 weeks.

The primary objectives of the analysis included the total symptom score (TSS), which comprised the nasal symptom score (NSS) including stuffy nose, nasal discharge, itching, and sneezing, and the non-nasal symptom score (NNSS) including itching and burning eyes, foreign body sensation in the eye, tearing, redness, and itching of the ears and possibly palate. Secondary objectives included discomfort caused by rhinitis, quality of life, and the incidence of adverse events.

Results

Five multicenter studies with a total of 3329 participants with a clinical history of seasonal AR to pollen allergen confirmed by skin prick test or specific IgE antibody examination met the inclusion criteria. All 5 studies compared bilastine with placebo, 2 studies also with cetirizine, in 1 study desloratadine was used as a comparator, and in another study fexofenadine.

Bilastine was more effective than placebo in terms of improving TSS, NSS, NNSS scores, reducing discomfort caused by rhinitis, and improving quality of life. The efficacy was comparable with other OAH, and there were no significant differences between bilastine, cetirizine, desloratadine, and fexofenadine in these aspects.

Participants in all 5 studies reported adverse events such as headache, somnolence, and fatigue. There were no significant differences in the incidence of adverse events between bilastine, placebo, and other OAH. The exception was lower somnolence with bilastine compared to cetirizine (based on 2 studies; n = 886; relative risk [RR] 0.38; 95% confidence interval [CI] 0.17−0.86; p = 0.02).

Conclusion

The efficacy and safety of bilastine in treating the overall symptoms of AR are comparable to other OAH, with the advantage of lower somnolence compared to cetirizine. 

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Source: Singh Randhawa A., Mohd Noor N., Md Daud M. K., Abdullah B. Efficacy and safety of bilastine in the treatment of allergic rhinitis: a systematic review and meta-analysis. Front Pharmacol 2022; 12: 731201, doi: 10.3389/fphar.2021.731201.