Choice of antimuscarinic agents for overactive bladder in the older patient: focus on darifenacin

The efficacy of nebivolol on spontaneously hypertensive rats with overactive bladder - an experimental study

INTRODUCTION

Overactive bladder (OAB) is a disease that significantly decreases quality of life. Adverse effects of the drugs currently used in OAB treatment limit their use in patients with hypertension. Nebivolol (a β₁-adrenergic receptor blocker) is approved for hypertension treatment, but also shows agonistic activity on β₃-adrenergic receptor, located in the urinary bladder. The aim of this study was to assess the impact of nebivolol on OAB symptoms and cardiovascular parameters in spontaneously hypertensive rats (SHR) - an animal model of OAB and hypertension.

MATERIAL AND METHODS

Female Wistar-Kyoto (WHY) and SHR rats were used in the experiments. Nebivolol was administered intra-arterially at a single daily dose of 0.05 mg/kg for 14 days. Subsequently, cystometry and bladder blood flow assessment were performed. Then, 24-hour measurement of heart rate, blood pressure, and urine production was carried out. In addition, the bladders of experimental rats were removed and processed to conduct biochemical analyses.

RESULTS

The main finding of this study is that the treatment with nebivolol resulted in an improvement of cystometric parameters characteristic for OAB in SHR. Nebivolol normalised blood pressure in SHR, while in WHY the cardiovascular parameters remained unchanged. Biomarkers characteristic for OAB were elevated in SHR compared to WHY, and nebivolol decreased their values in SHR while it had no influence on WHY.

CONCLUSIONS

Nebivolol alleviates OAB symptoms and normalises blood pressure in SHRs. These results suggest that nebivolol may be a useful treatment alternative for OAB patients with pre-existing hypertension.

Anticholinergic drugs and risk of dementia: Time for action?

Evidence suggests that the prescription of bladder anticholinergics is increasing. Recent studies have accentuated concerns about whether certain prescribed medications could increase risk of dementia, including anticholinergic drugs, and specifically anticholinergics used for bladder symptoms. Nevertheless, it can be difficult to draw together the evidence to review the case for possible causation. Recognising this issue in 1965, Bradford-Hill set out nine criteria to help assess whether evidence of a causal relationship could be inferred between a presumed cause and an observed effect. In this commentary, we explore the extent to which associations between anticholinergics and dementia satisfy the Bradford-Hill criteria and examine the potential implications. First, we look at studies that have examined the relationship between anticholinergic drugs with urological properties (bladder drugs) and the onset of dementia, and then present those studies which specifically focus on the cognitive effects of bladder drugs that affect muscarinic receptors in the brain versus the bladder on older people along with suggestions for future research. We also discuss the risks and benefits of these drugs for treating overactive bladder. If it can be shown that certain medications carry a specific risk of dementia, it is possible that initiatives to change prescribing could become a key tool in reducing the risk of dementia and may be easier to implement than some lifestyle changes.

Treatment of Overactive Bladder in the Elderly Female: The Case for Trospium, Oxybutynin, Fesoterodine and Darifenacin

Overactive bladder (OAB) is a common constellation of lower urinary tract storage symptoms that causes a significant impact on a person's quality of life. The elderly may be disproportionally impacted by these symptoms due to concomitant poor mobility, comorbid conditions such as diabetes and heart failure, and polypharmacy. While behavioral modification and pelvic floor muscle training should be considered first-line treatment options, pharmacotherapy remains the backbone of the therapeutic regimen. Trospium, oxybutynin, fesoterodine, and darifenacin all have unique properties that may confer certain advantages in the elderly population. The hydrophilicity and quaternary amine structure of trospium may limit its ability to cross the blood-brain barrier and thus minimize impact on cognition in the elderly. In its oral form, oxybutynin may have the most significant effect on cognition; however, the transdermal preparations may be favorable in the elderly population due to the ability to avoid first-pass metabolism and its limited antimuscarinic adverse effects. Fesoterodine may be the most extensively studied OAB medication in the elderly population. Darifenacin has a strong affinity for the M3 receptor in the bladder, while having a weak affinity for the M1 receptor commonly found in the brain. It must be noted that all muscarinic receptor antagonists are associated with common adverse effects to some degree, and frequent re-evaluation of the elderly patient is necessary to confirm the proper benefit-to-risk profile.

A prospective, comparative study of the occurrence and severity of constipation with darifenacin and trospium in overactive bladder

INTRODUCTION

Darifenacin and trospium are the commonly used antimuscarinics in the management of overactive bladder (OAB). Constipation is the second most common treatment related side-effect. Though its incidence with the above two medications is known, data on their comparative severity and impact on patient's well-being is lacking.

MATERIALS AND METHODS

Sixty subjects with OAB included in the study were randomized in 1:1 fashion to receive either darifenacin 7.5 mg OD or trospium extended release 60 mg OD. Treatment response was monitored using overactive bladder symptom score (OABSS). The severity of constipation was assessed using McMillan & Williams Constipation assessment scale (CAS), Bristol stool form scale and Knowles-Eccersley-Scott-Symptom (KESS) questionnaire score administered at baseline, 2 and 4 weeks of treatment.

RESULTS

OABSS improved significantly, -5.80 ± 3.99 (p = 0.0005) and -5.27 ± 2.98 (p = 0.0005) in darifenacin and trospium groups respectively. However, the difference between the two groups was not significant either at 2 weeks (p = 0.952) or 4 weeks (p = 0.654) of treatment. A significant decrease in stool consistency was noted with darifenacin treatment (p < 0.05), but the same was not seen with trospium (p = 0.076). There was no significant difference in scores of KESS questionnaire between baseline, 2 weeks and 4 weeks, both within the group and between the groups (p > 0.05). McMillan & Williams CAS scores increased at week 2 and week 4, in comparison with baseline scores in both darifenacin and trospium treated patients, however, the difference between the two groups was not statistically significant (p > 0.05).

CONCLUSION

Darifenacin and trospium are equally efficacious and comparable in tolerability in terms of constipation severity and its impact on patient well-being.

Management of OAB in those over age 65

The International Continence Society (ICS) defines overactive bladder (OAB) as an association of symptoms including "urgency, with or without urge incontinence, usually with increased frequency and nocturia". This conditon has been associated with a decrease in quality of life and a higher related risk of overall health condition decrease, and is rising since its prevalence increases with age and the forecast for the world population estimates an increase of those over 65 years old. Aging alone can be considered a major risk factor for developing OAB symptoms that are considered multifactorial and due to body tissue and anatomic changes, lifestyle-associated factors, comorbidities and personal characteristics. The high prevalence of this condition and multiple etiology factors makes of its treatment a challenge-especially in the older population. A major concern over OAB treatment of elderly patients is the risk of cognitive side effects due to the pharmacologic treatment with anticholinergic drugs. First-line treatment for OAB symptoms are the use of pharmacologic therapy with antimuscarinic drugs, which has been proved to be effective in controlling urgency, urge incontinence episodes, incontinence episodes, and nocturia. The impact caused by this condition is significant regarding the economic and human costs associated bringing into attention the need of studying and reviewing this specific population. Conservative Management and Lifestyle Modifications: Behavioral therapy's aims are to reduce urinary frequency and urgency to an accepted level and to increase bladder outlet volume. It consists of actions to teach patients to improve and learn bladder control. Lifestyle modifications are a conjunct of daily activities that can be managed to have the lowest interference on the functioning of the urinary tract. Pharmacologic Therapy: There are various medications with antimuscarinic properties available for the treatment of OAB symptoms. The most commonly used are oxybutinin, tolterodine, solifenacin, darifenacin, fesosterodine and trospium. Second-line Therapy: OAB treatment accounts for some refractory to conventional treatment patients who will require alternative therapies to achieve improvement of symptoms as the use of intradetrusor injection of botulinum A toxin by binding to receptors on the membrane of cholinergic nerves causing temporary chemodenervation and consequent muscle relaxation. Neuromodulation is also an effective therapy that aims to achieve inhibition of detrusor activity by continuous neural stimulation through peripheral nerves as the use of the tibial nerve or central as it is performed by direct spine stimulation on sacral roots through the implantation of an automated generator. In conclusion, evidence from the literature has shown that antimuscarinic treatment of OAB in the elderly population is safe and effective in improving symptoms and patient's quality of life. Managing OAB symptoms in this population is a great challenge. An optimal therapeutic approach to treat should involve medical treatment with drug and behavioral therapy in addition to lifestyle advice.

The safety and efficacy of tolterodine extended release in the treatment of overactive bladder in the elderly

After lifestyle and behavioral measures to control overactive bladder, the mainstay of pharmacological treatment is the use of antimuscarinic therapy. Overactive bladder predominantly affects older people, who experience the most severe disease, and are also at a greater risk of side effects from antimuscarinic therapy. Thus it is imperative that data are available on the efficacy and tolerability of this group of drugs when used in older people. This article reviews the pathophysiology of the condition, its effect on the elderly and the evidence for the use of extended release tolterodine in the elderly using data from placebo and active drug controlled studies.