Which patient group is at higher risk for cognitive side effects from antimuscarinic therapy?

• A. Older adults
• B. Children
• C. Athletes
• D. Older adults with cognitive impairment

Answer: (D)

Antimuscarinic drugs can cause cognitive side effects because they block muscarinic receptors in the brain, reducing acetylcholine signaling that supports attention, memory, and learning. This central anticholinergic impact is especially problematic in older adults, who often have age-related brain changes and may be taking multiple medications, increasing their overall anticholinergic burden. When cognition is already impaired, the brain has less reserve to cope with additional disruption, so even standard doses can lead to noticeable worsening in memory, confusion, or attention. That combination—age-related vulnerability plus existing cognitive impairment—makes older adults with cognitive impairment the group at the highest risk for cognitive side effects from antimuscarinic therapy.

Older adults in general are still at risk, but without preexisting cognitive impairment the effect tends to be less dramatic. Children and athletes don’t have the same level of baseline cognitive vulnerability to central anticholinergic effects, so their risk for cognitive side effects is comparatively lower.