Which symptom is commonly associated with antihistamine use?

Antihistamines are commonly used to alleviate allergic reactions by blocking the action of histamine in the body. One well-known side effect of many antihistamines, particularly the first-generation types like diphenhydramine, is dry mouth. This occurs because antihistamines can inhibit the secretion of saliva, leading to a sensation of dryness in the mouth, which can be uncomfortable for users.

Dry mouth can also contribute to other oral health issues, and it's important for users to be aware of this side effect if they are taking antihistamines, especially over a long period. It is a direct manifestation of the anticholinergic effects of these medications, which is a common pharmacological property of many first-generation antihistamines.

While there are other potential side effects associated with antihistamines, such as sedation or drowsiness, the significance of dry mouth is particularly noteworthy in discussions about the common side effects of these medications.