Anticholinergic drugs block the action of acetylcholine and can treat several conditions like overactive bladder, COPD, and urinary incontinence. The use of anticholinergic drugs is linked with the increased risk of disorders like dementia. This study aims to identify the associations between exposure to different classes of anticholinergic drugs and the risk of dementia.

This is a case-control study that included a total of 40,770 patients aged 65-99 with a confirmed diagnosis of dementia. The study also included 283,933 controls without dementia. The participants were assigned to daily defined doses of anticholinergic drugs. The primary outcome of the study was Odds Ratios (OR) for incident dementia.

14,453 (35%) participants and 86 ,03 (30%) controls were assigned to at least one anticholinergic drug with an ACB score of 3 during exposure. The OR for all anticholinergic drugs with an ACB score of 3 was 1.11. The findings suggested that increasing average ACB score was associated with an increased risk of dementia. When classified by drug class, gastrointestinal drugs (ACB: 3) were not related to an increased risk of dementia. Contrarily, antidepressant, urological, and antiparkinson drugs increased the risk of dementia.

The research concluded that the risk of dementia was significantly associated with antidepressant, urological, and antiparkinson drugs, but not with gastrointestinal drugs.