Sedative effects of antihistamines: safety, performance, learning, and quality of life

Antihistamines are frequently part of the treatment regimen for seasonal and perennial allergic rhinitis occurring alone or in conjunction with associated airway disorders, such as asthma, sinusitis, and otitis media with effusion. These agents are also frequently prescribed for the treatment of urticaria to eliminate the need for long-term corticosteroids. This paper reviews the side-effect profile of the sedating and nonsedating agents (a classification given these drugs by the US Food and Drug Administration) in terms of patient satisfaction and quality-of-life parameters. Because the sedating antihistamines cross the blood-brain barrier more quickly and easily than the nonsedating antihistamines, they produce more central nervous system (CNS) effects, further exacerbating the decreases in decision-making, verbal learning, and psychomotor skills already experienced by the patient with allergic rhinitis. In contrast the now-preferred nonsedating agents do not readily cross the blood-brain barrier, do not produce CNS side effects, and, therefore, do not cause sedation or performance impairment. The nonsedating agents provide a safer alternative for patients with allergic rhinitis. Their use can increase patient satisfaction with the health care received.