Evaluation of the Optimal Oral Antihistamine for Patients With Allergic Rhinitis

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.