Review of cognitive impairment with antimuscarinic agents in elderly patients with overactive bladder.

Overactive bladder (OAB) will become an increasingly prevalent problem as the proportion of older people in the population increases over the next 20 years. In addition to the urological symptoms (urinary urgency, with or without urgency incontinence, usually with increased daytime frequency and nocturia), OAB is associated with other problems in older patients, especially an increased risk of falls and fractures. The bother caused by OAB needs not be an inevitable consequence of ageing, because the symptoms can usually be alleviated, even in frail older people. Pharmacological treatment for OAB involves the use of antimuscarinic agents, whose efficacy and safety profiles depend on their interactions with muscarinic receptors that are widely distributed throughout the body. Interactions between antimuscarinics and M(1) receptors in the central nervous system may have the potential to cause cognitive impairment in older people, depending on muscarinic receptor binding profiles, lipophilicity and the ability to cross the blood brain barrier. Concerns over the possibility of cognitive impairment have contributed to an under-utilisation of antimuscarinics in the geriatric population, despite the high prevalence and severity of OAB in older subjects. Antimuscarinic agents should be actively considered for elderly patients with OAB, but it is desirable to establish the cognitive risk for every type of antimuscarinic, using robust cognition assessment methods.