Antihistamines targeting the histamine H₁ receptor play an important role in improving and maintaining the quality of life of patients with allergic rhinitis. For more effective and safer use of second-generation drugs, which are recommended by various guidelines, a classification based on their detailed characteristics is necessary. Antihistamines for first-line therapy should not have central depressant/sedative activities.
Among the non-sedating group, fexofenadine and bilastine are classified into “non-brain-penetrating antihistamines”.
This review summarizes that the non-brain-penetrating antihistamines should be chosen for the first-line therapy of mild allergic rhinitis.
Bilastine shows a long drug-target residence time at the H1 receptor (73 ± 5 min) and this results in a prolonged H1 receptor antagonism in vitro (Ca2+ mobilization in Fluo-4 loaded HeLa cells), following a washout of unbound antagonist. Hence, the long residence time of bilastine can explain the observed long duration of drug action in vivo.
Bilastine has a proven, long-term safety record with use by over 71 million patients in over 104 countries. This novel, second generation antihistamine is non-sedating due to the fact that it does not cross the blood brain barrier. As well, bilastine is not metabolized and does not interact with CYP450.
A number of second-generation non-sedating antihistamines are used in clinical practices over the world. However, long-term safety and efficacy have not been proved high level evidence based medicine.
In conclusion, long-term treatment with bilastine 20 mg once daily for 52 weeks is safe and well tolerated in Japanese patients with hronic spontaneous urticaria (CSU) or pruritus associated with skin diseases. Bilastine improved disease symptoms of both conditions early in treatment, and the efficacy was maintained throughout the treatment.