Risk of delirium associated with antimuscarinics in older adults: A case-time-control study.

The study found that oxybutynin but not solifenacin is associated with a risk of new-onset delirium in older adults. The higher blockade of M1 and M2 receptors by oxybutynin is likely to contribute to delirium than solifenacin, which is highly selective for the M3 receptor subtype. Therefore, the treatment choice with an M3 selective agent must be given due consideration, particularly in those with pre-existing cognitive impairment.