Overactive bladder in the elderly : A guide to pharmacological management

Overactive bladder (OAB) is a common condition characterised by the symptoms of urinary frequency and urgency, with or without urge incontinence and nocturia. The prevalence of OAB increases markedly with age in both men and women. OAB can have a detrimental effect on physical functioning and psychological well-being, as well as significantly reducing quality of life. Antimuscarinic therapy -- with or without behavioural therapy -- represents the most common treatment for patients with OAB. Several antimuscarinic agents are currently available for the treatment of OAB in adults, including oxybutynin, tolterodine, trospium chloride, darifenacin and solifenacin. The antimuscarinics all appear to exert their clinical effect through inhibition of the bladder muscarinic receptors, but they vary both in structure and in their functional profile. While efficacy has been demonstrated in adult populations (including patients >65 years of age), few studies have been reported specifically in a geriatric population, and antimuscarinics are often underutilised in the elderly despite the marked increase in the prevalence of OAB in this age group. One explanation for this apparent underuse of an effective treatment option may be concerns about the frequency of anticholinergic adverse events, such as dry mouth; the likelihood of detrimental CNS effects, including cognitive impairment and sleep disturbances; and the potential for harmful interactions with existing pharmacotherapy. When selecting an antimuscarinic agent for the management of an elderly patient presenting with OAB, in addition to considering evidence of clinical efficacy and tolerability, issues of safety specific to an older population should be borne in mind. In particular, the likelihood of detrimental CNS effects should be considered, including cognitive impairment and sleep disturbances, secondary to anticholinergic load. Oxybutynin and tolterodine have both been associated with cognitive adverse events and effects on sleep architecture and quality. In contrast, trospium chloride and darifenacin do not appear to be associated with cognitive adverse events and trospium chloride does not negatively affect sleep architecture or quality. Biotransformation by the cytochrome P450 (CYP450) system is an important step in the activation or elimination of a large number of drugs, including oxybutynin, tolterodine, darifenacin and solifenacin, raising the possibility of clinically relevant and potentially serious