Cognitive Effects of Anticholinergic Load in Women with Overactive Bladder

Overactive bladder syndrome (OAB) is defined as urinary urgency, usually accompanied by frequency and nocturia, with or without urgency incontinence, in the absence of urinary tract infection or other obvious pathology. The mainstay of treatment of OAB is anticholinergic/antimuscarinic medication. These drugs block muscarinic receptors throughout the body, not only the bladder, including in the brain, which may lead to cognitive side effects. Anticholinergic load or burden is the cumulative effect of taking drugs that are capable of producing anticholinergic adverse effects. The elderly are more susceptible to these effects, especially as there is increased permeability of the blood brain barrier. The anticholinergic drugs for OAB are able to enter the central nervous system and lead to central side effects. There is increasing evidence that a high anticholinergic load is linked to the development of cognitive impairment and even dementia. Some studies have found an increased risk of mortality. In view of this, care is needed when treating OAB in the elderly. Trospium chloride is a quaternary amine anticholinergic, which has a molecular structure, which theoretically means it is less likely to cross the blood brain barrier and exert central side effects. Alternatively, mirabegron can be used, which is a beta-3 adrenoceptor agonist, which does not add to the anticholinergic load or exert central nervous system side effects. Conservative therapy can be used as an alternative to pharmacological treatment in the form of behavioral modification, fluid management and bladder retraining. Neuromodulation or the use of botox can also be alternatives, but success may be less in the older adult and will require increased hospital attendances.