The prevalence of allergic diseases in the Asia-Pacific region is expected to rise over the next 20 years, driven by rapid economic development and urbanization. Allergic diseases have high socioeconomic impact by impairing productivity and quality of life, and the impact may be greater in Asia-Pacific than in Europe due to the presence and predominance of perennial allergens.

Allergic rhinitis and urticaria are two of the most well-studied allergic conditions, and international guidelines on the management of these two conditions are well established. Both the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines [J Allergy Clin Immunol 2010;126:466–476] and the European Academy of Allergy and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum/World Allergy Organization guidelines [Allergy 2014;69:868–887] recommend H1–antihistamines as first-line treatment for allergic rhinitis and urticaria, respectively. Importantly, both guidelines indicate preference for second-generation antihistamines over the first-generation antihistamines, due to their high efficacy, pharmacokinetics allowing for less frequent dosing and lack of anticholinergic and sedative side effects. These guidelines are commonly used in the Asia-Pacific for lack of local guidelines in many countries in the region.

Asia-Pacific treatment algorithm for allergic rhinitis and urticaria

To aid physicians in the region in clinical decision-making in the treatment of allergic rhinitis and urticaria, a 10-member expert panel of five dermatologists, three otorhinolaryngologists and two allergologists from Hong Kong, Malaysia, the Philippines, Singapore, Thailand and Vietnam reviewed the available literature on antihistamine treatment for allergic rhinitis and urticaria with the goal of developing an appropriate treatment algorithm [Clin Mol Allergy 2017;15:19]. The clinicians considered the clinical practices of their peers and general practitioners in their respective countries, and identified common patient profiles to understand the practical considerations and/or limitations that influence antihistamine treatment in allergic rhinitis and urticaria. A survey was also used to define clinicians’ views, preferences, and considerations for choice of an appropriate antihistamine.

The resulting treatment algorithms for allergic rhinitis (Figure 1) and urticaria (Figure 2) indicate the presence of concomitant disease as the first consideration for choosing an appropriate antihistamine. The second clinical consideration is the presence of hepatic or renal impairment. The third, and often neglected consideration, is the patient’s need for a high level of concentration at work or daily living. Of note, the two algorithms indicate bilastine as an appropriate first-line antihistamine for all patient groups (ie, whether allergic rhinitis or urticaria, with or without concomitant disease, hepatic or renal impairment, or even in those who require a high level of concentration at work or in daily life).





The clinician survey results also showed bilastine is a preferred choice due to its high efficacy and safety, suitability for special patient populations, and lack of sedative effects (Table). Importantly, the expert panel consensus encouraged general practitioners to adhere to the treatment recommendations due to the established efficacy and safety advantage of second-generation antihistamines over first-generation agents.



Bilastine: An ARIA-appropriate H1–antihistamine

The emergence of bilastine as an appropriate and preferred antihistamine in the previously described Asia-Pacific expert panel consensus mirrors the findings of a systematic review on bilastine that evaluated seven second-generation antihistamines against the ARIA criteria of “properties that should be met by oral H1-antihistamines” [Ther Clin Risk Manage 2016;12:585–597]. The systematic review showed that bilastine exhibited the following profile: has marked H1 receptor selectivity; indicated for allergic rhinoconjunctivitis, allergic rhinitis, and urticaria; requires no dose adjustment in hepatic/renal impairment/elderly; lacks clinically relevant drug/alcohol interactions; and lacks sedative potential. Among the seven antihistamines, bilastine scored the highest in terms of ARIA-desired features for a second-generation H1-antihistamine.

Conclusion

In the Asia-Pacific region, the presence of concomitant disease and hepatic/renal impairment, as well as the patient’s need for a high level of concentration at work or daily living, are important clinical considerations for choosing an appropriate antihistamine to treat allergic rhinitis or urticaria. Bilastine is an appropriate first-line antihistamine for all patient groups based on these considerations, and is a highly preferred second-generation oral H1-antihistamines due to multiple ARIA-defined features.

Clinician’s point of view

Role of bilastine in the treatment of allergic rhinitis and urticaria

An interview with Associate Professor Marysia Stella T. Recto

Associate Prof Marysia Stella T. Recto
Adult and Paediatric Allergy and Immunology
University of the Philippines-Philippine General Hospital
Manila, Philippines

Introduction

Allergic rhinitis and urticaria are two of the most common clinical conditions seen by allergy specialists and GPs. Allergic rhinitis affects around 400 million people worldwide [Asia Pac Allergy 2012;2:129–135] while the prevalence of urticaria is less clear, with an estimated yearly prevalence of 1 percent [Allergy Asthma Immunol Res 2017;9:189–190], and is likely to be underestimated.

Allergic rhinitis is largely immunoglobulin E (IgE) mediated, whereas urticaria may have diverse allergic and nonallergic mechanisms. Nonetheless, the underlying processes of both conditions culminate in the release of histamine from mast cells, which causes allergy symptoms such as sneezing, nasal congestion, nasal itching, and rhinorrhoea for allergic rhinitis, and localized or generalized rashes, wheals, and pruritus for urticaria. Though allergic rhinitis and urticaria have different and distinct characteristics, both conditions are recurrent, and treatment is usually prolonged.

Guideline-directed management

Allergic rhinitis and urticaria respond to antihistamine treatment. Current international guidelines, namely the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines [J Allergy Clin Immunol 2010;126:466–476] and the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network/European Dermatology Forum/World Allergy Organization (EAACI/GA(2)LEN/EDF/WHO) guidelines [Allergy 2014;69:868–887] recommend second-generation antihistamines over older generation agents as first-line treatment for both conditions. Adherence to these guidelines is associated with improved treatment success, but many patients still do not receive guideline-recommended treatment because of low guideline adherence on the part of the clinicians. Other factors include low awareness among GPs of the existence of the current guidelines and the high cost of some guideline-recommended treatments.

Second-generation oral H1 antihistamines, for example bilastine, are preferred over the first- generation antihistamines because of their lack of anticholinergic and sedative side effects, a desired property for most patients especially those with active lifestyle, those that require optimal alertness (eg, students) and high level of concentration at work (eg, drivers, pilots, and those that operate heavy machinery). Aside from their nonsedating properties, second-generation H1 antihistamines are only taken once daily, with quick onset of action, which favour convenience and compliance and may be more cost-effective. On top of these benefits, second-generation H1 antihistamines could have anti-inflammatory effects when dosage is increased which could help improve comorbid allergic conditions a patient may be experiencing. [Am J Respir Med 2002;1:27–34]

Bilastine the antihistamine of choice

Bilastine, the newest second-generation antihistamine, could be considered as a good treatment option for allergic diseases because it has less sedative potential than other second-generation antihistamines, primarily because of its inability to cross the blood-brain barrier. A clinician survey among Asian practitioners also showed that bilastine is the preferred choice for allergic rhinitis and urticaria because of the following reasons: 1) bilastine’s efficacy for both allergic rhinitis and urticaria is supported by extensive clinical evidence; 2) bilastine has long-term tolerability profile which favours improved adherence to prolonged therapy; 3) bilastine is safe even in patients with concomitant disease (asthma, cardiovascular disease); 4) bilastine does not require dose adjustments in patients with hepatic or renal impairment. [Clin Mol Allergy 2017;15:19]

Of note, bilastine’s pharmacokinetic properties, efficacy, and tolerability profile makes it an ideal oral second-generation H1 antihistamine for the management of both allergic rhinitis and urticaria.

Conclusion

Second-generation antihistamines, including bilastine, are the preferred first-line treatment in the guideline-directed management of allergic rhinitis and urticaria, owing to their established efficacy and long-term tolerability. When choosing an appropriate second-generation antihistamine, clinicians should consider clinical evidence of efficacy and long-term safety, including the individual needs of their patients. For most patients, bilastine fulfils these considerations and facilitates adherence to guideline-recommended therapies for allergic rhinitis and urticaria.