Which medication class may cause significant sedation as a side effect?

Antihistamines are known to cause significant sedation as a common side effect, particularly first-generation antihistamines such as diphenhydramine and chlorpheniramine. These medications work by blocking the H1 histamine receptor, which not only helps alleviate allergy symptoms but can also cross the blood-brain barrier, leading to central nervous system effects, including drowsiness and sedation. This sedative effect is particularly pronounced with first-generation antihistamines, while second-generation antihistamines tend to have a far lower incidence of sedation due to their reduced ability to penetrate the central nervous system.

In contrast, medications from other classes such as beta-agonists, corticosteroids, and leukotriene modifiers do not typically produce sedation. Beta-agonists are primarily used for bronchodilation in conditions like asthma and COPD and are not associated with sedative effects. Corticosteroids, which are anti-inflammatory agents, can have various side effects, but significant sedation is not one of them. Leukotriene modifiers, used to manage asthma and allergies, likewise do not exhibit sedative properties.