Which drug is known for potentially causing xerostomia?

Benadryl, which is the brand name for diphenhydramine, is an antihistamine commonly used to relieve allergy symptoms. One of its well-documented side effects is xerostomia, or dry mouth. This occurs because antihistamines work by blocking histamine receptors, which in turn can inhibit the secretion of saliva from the salivary glands. As a result, patients taking Benadryl may experience a reduction in saliva production, leading to the sensation of a dry mouth.

In contrast, while other options like fluticasone and cyclosporine may have side effects, they are not primarily associated with causing xerostomia. Fluticasone is a corticosteroid used mainly for controlling inflammation in conditions such as asthma and allergies, and while it can have an impact on oral health, dry mouth is not its characteristic side effect. Cyclosporine is an immunosuppressant that may cause other oral health issues, like gingival hyperplasia, but again, xerostomia is not a well-recognized effect. Epinephrine, used primarily in emergency settings for severe allergic reactions, does not typically result in dry mouth either, as its mechanism of action and application differ significantly from that of antihistamines