nonsedating

Nonsedating is a descriptive term used for drugs that aim to produce little or no sedation. It is most often applied to antihistamines, especially second-generation agents, but it is not a formal pharmacological category. The term generally reflects design features that limit central nervous system effects and/or confer more peripheral action.

In antihistamines, sedation arises when a drug crosses the blood-brain barrier and blocks central H1 receptors. Nonsedating antihistamines are developed to minimize brain exposure or to be selective for peripheral H1 receptors, reducing drowsiness while still countering allergic symptoms. Nevertheless, individual response varies, and coadministration with alcohol or other sedatives can increase sedation in some people.

Common examples that are marketed or described as nonsedating include fexofenadine, loratadine, desloratadine, and cetirizine in many regions; rupatadine is also considered nonsedating by many sources. Some products marketed as nonsedating may still cause mild drowsiness in sensitive individuals, especially at higher doses.

The term is used in consumer labeling and clinical guidance but does not guarantee the complete absence of sedation or other adverse effects. Nonsedating status can depend on dose, age, liver function, and drug interactions, and individual variability may be substantial.

See also: sedating antihistamines, antihistamines, H1 antagonists.