Antimuscarinics for the treatment of overactive bladder: A review of central nervous system effects

Presence of central nervous system, cardiovascular and overall co-morbidity burden in patients with overactive bladder disorder in a real-world setting

OBJECTIVE

•  To determine the proportion of patients with overactive bladder (OAB) potentially at risk for adverse events by assessing their pre-existing central nervous system (CNS), cardiovascular (CV) and other co-morbidities.

PATIENTS AND METHODS

•  The GE Centricity Electronic Medical Record database was utilized to identify patients with a diagnosis of OAB using International Classification of Diseases, Ninth Revision (ICD-9) codes or a prescription between 1 January 1996 and 30 March 2007 for an OAB anti-muscarinic agent. •  Matched non-OAB patients were assigned the same index date as the corresponding OAB patient. Based on the presence of ≥ one pharmacy claim for an OAB anti-muscarinic agent, the OAB cohort was stratified as treated or untreated. A random sample of age- and gender-matched patients formed a non-OAB control cohort. •  An additional and separate analysis focusing on all co-morbidities was performed examining non-OAB patients who were matched to OAB patients on 1:1 propensity score matching, based on age, body mass index (BMI) and gender at baseline. •  Charlson Comorbidity Index (CCI), using ICD-9 codes, and the Chronic Disease Score (CDS), using prescribed drugs, were calculated.

RESULTS

•  When compared with non-OAB patients (N= 77,272; 83.2% women; median age 64 years), OAB patients (N= 41,440; 83.6% women; median age 65 years) had more overall CNS co-morbidities (45.4 vs 29.0%; P < 0.001). •  In addition, OAB patients had a higher use of medications with anti-muscarinic effects (39.6 vs 25.4%; P < 0.001). OAB patients were also more likely to have CV co-morbidities (57.6 vs 44.6%; P < 0.001). •  CNS co-morbidities were slightly more common in untreated (n= 8 106) than in treated (n= 33 334) OAB patients (47.2 vs 45.0%; P < 0.001). CV co-morbidities were higher in treated OAB patients (58.8 vs 53.7%; P < 0.001). •  In the additional separate analysis, which focused on all co-morbidities, patients with OAB had higher mean CCI and CDS scores than patients without OAB (CCI: 1.17 vs 1.11 [P < 0.001]; CDS: 2.95 vs 1.74 [P < 0.001]). •  After controlling for other covariates, the linear regressions (n= 22,544) showed that OAB patients had higher CCI and CDS than patients without OAB.

CONCLUSIONS

•  Among OAB patients, CNS, CV and all co-morbidities were more prevalent than in non-OAB patients. •  Prior exposure to CNS medications was more prevalent in OAB patients who received anti-muscarinic treatment than in those who did not. •  Co-morbidities and concomitant medications affecting the CNS and the CV system should be taken into account when making the decision on the most appropriate OAB treatment option for each individual patient.

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.