Questionnaire Survey on Possible Oral Dryness for Comparisons among Three Α1-adrenergic Receptor Antagonists (naftopidil vs. Tamsulosin

Hypothesis / aims of study It is clinically known that anticholinergic agents, commonly used for treating overactive bladder, etc., act on the muscarinic receptor in salivary glands, causing dry mouth as an adverse effect. Not only the muscarinic receptor but also the α1-adrenergic receptor are present in human salivary glands, and are thought to accelerate saliva production. The common adverse events associated with α1-adrenergic receptor antagonists include orthostatic hypotension and dizziness. However, clinical research focusing on the association between α1-adrenergic receptor antagonists and oral dryness is very limited. Therefore, we conducted a cross-sectional study on current oral dryness using a questionnaire in patients prescribed an oral α1-adrenergic receptor antagonist for benign prostatic hyperplasia.