Evaluation of the Optimal Oral Antihistamine for Patients With Allergic Rhinitis

Abstract

Because of its bothersome symptoms, allergic rhinitis (AR) is 1 of the top 10 reasons for patient visits to primary care physicians. This highly prevalent disease also results in loss of productivity, both at work and in school. Oral antihistamines are one of the most frequently prescribed medications for the management of AR and, with several agents available, it is important to discern the specific benefits and detriments of each. To assess the differences in efficacy and safety factors among antihistamines, the Individual therapeutic window of each agent can be used as a comparative reference tool because it defines the dose range over which an antihistamine is efficacious and free of adverse effects. As such, the therapeutic window includes both undesired effects, such as sedation, and desired properties, such as rapid onset of action, long duration of efficacy, broad age range of applicability, and potential to Improve quality of life. Therefore, agents with broad therapeutic windows, based on both efficacy and safety, are expected to be more favorable; this therapeutic window should be understood by the primary care physician when prescribing a medication.

The diagnosis and management of rhinitis: An updated practice parameter

“…307 Among the newer, nonsedating antihistamines, no single agent has been conclusively shown to have superior efficacy. 326,327 A recent meta-analysis found ebastine (an agent not available in the United States) superior to loratadine for the decrease in mean rhinitis symptom scores in seasonal allergic rhinitis. 915 Several studies have found cetirizine to be superior to loratadine, although in 1 study, the differences were not statistically significant.…”

“…No single agent has been conclusively shown to have superior efficacy. 326,327 Exceeding the recommended dosage may result in increased sedation with many of these products 309,323,328-330 that do not produce sedation at recommended doses. Although antihistamines can be used on an intermittent basis, such as for episodic allergic rhinitis, it has been shown that continuous treatment for seasonal or perennial allergic rhinitis is more effective, 331 primarily because of unavoidable, ongoing allergen exposure.…”

Burden of allergic rhinitis: Results from the Pediatric Allergies in America survey

“…Indeed, bothersome symptoms of nasal allergies in children and adults contribute to the heavy burden of nasal allergies such that AR is ranked as one of the top 10 reasons for primary care physician visits in the United States. 23,24 …”

Pharmacotherapy for allergic rhinitis

“…There are 6 classes of first generation antihistamines, including ethanolamines (diphenhydramine: Benedryl), alkylamines (chlorpheniramine: Chlor‐Trimeton), piperazines (hydroxyzine: Atarax), and phenothiazines (promethazine: Phenergan). These early antihistamines are lipophilic and readily cross the blood‐brain barrier resulting in central nervous system (CNS) side effects, including sedation and decreased cognitive abilities, motor performance, and ability to drive . First‐generation antihistamines are also limited by adverse effects due to anticholinergic stimulation, resulting in blurry vision, dry mouth, and increased mucous viscosity.…”

“…The anticholinergic side effects seen in earlier antihistamines are not as prevalent with second‐generation medications. The second‐generation oral antihistamines appear to have similar efficacy …”