The medical treatment of overactive bladder, including current and future treatments

Research Findings on Overactive Bladder

Several physiopathologic conditions lead to the manifestation of overactive bladder (OAB). These conditions include ageing, diabetes mellitus, bladder outlet obstruction, spinal cord injury, stroke and brain injury, Parkinson's disease, multiple sclerosis, interstitial cystitis, stress and depression. This review has discussed research findings in human and animal studies conducted on the above conditions. Several structural and functional changes under these conditions have not only been observed in the lower urinary tract, but also in the brain and spinal cord. Significant changes were observed in the following areas: neurotransmitters, prostaglandins, nerve growth factor, Rho-kinase, interstitial cells of Cajal, and ion and transient receptor potential channels. Interestingly, alterations in these areas showed great variation in each of the conditions of the OAB, suggesting that the pathophysiology of the OAB might be different in each condition of the disease. It is anticipated that this review will be helpful for further research on new and specific drug development against OAB.

Purinergic signalling in the urinary tract in health and disease

Purinergic signalling is involved in a number of physiological and pathophysiological activities in the lower urinary tract. In the bladder of laboratory animals there is parasympathetic excitatory cotransmission with the purinergic and cholinergic components being approximately equal, acting via P2X1 and muscarinic receptors, respectively. Purinergic mechanosensory transduction occurs where ATP, released from urothelial cells during distension of bladder and ureter, acts on P2X3 and P2X2/3 receptors on suburothelial sensory nerves to initiate the voiding reflex, via low threshold fibres, and nociception, via high threshold fibres. In human bladder the purinergic component of parasympathetic cotransmission is less than 3 %, but in pathological conditions, such as interstitial cystitis, obstructed and neuropathic bladder, the purinergic component is increased to 40 %. Other pathological conditions of the bladder have been shown to involve purinoceptor-mediated activities, including multiple sclerosis, ischaemia, diabetes, cancer and bacterial infections. In the ureter, P2X7 receptors have been implicated in inflammation and fibrosis. Purinergic therapeutic strategies are being explored that hopefully will be developed and bring benefit and relief to many patients with urinary tract disorders.

Cost effectiveness of fesoterodine and tolterodine for the treatment of overactive bladder with urge urinary incontinence in Spain and Finland

BACKGROUND

Overactive bladder is a prevalent condition worldwide that is associated with a considerable burden, both on the patient and on society.

OBJECTIVE

Our objective was to assess the economic value of fesoterodine compared with tolterodine extended release (ER) for the treatment of overactive bladder (OAB) with urge urinary incontinence (UUI) in Spain and Finland.

METHODS

A decision-tree economic model estimated the 52-week costs and quality-adjusted life-years (QALYs) of OAB/UUI patients initiating treatment with fesoterodine 4 mg/day or tolterodine ER. Individuals were evaluated for treatment response (UUI fewer than one episode/day) and persistence at weeks 4, 12, and 24. Titration from fesoterodine 4 mg/day to 8 mg/day was permitted at week 4. At week 12, non-responders discontinued treatment permanently. Efficacy, discontinuation, and utility data were derived from four clinical trials of fesoterodine. OAB-related costs, including physician visits, laboratory tests, incontinence pads, and comorbidities (fracture, skin infection, urinary tract infections, depression, and nursing home) were also included.

RESULTS

A total of 19.5 % and 18.0 % of fesoterodine and tolterodine ER patients remained on treatment until week 52, respectively. QALYs were higher with fesoterodine than tolterodine ER (0.762 vs. 0.760). In Spain, fesoterodine treatment had higher total costs than (generic) tolterodine ER (€6,697 vs. 6,597), resulting in a cost of €15,633/QALY gained. In Finland, fesoterodine was cost saving relative to (non-generic) tolterodine ER (€7,885 vs. 8,024). Sensitivity analysis confirmed that these findings were robust to the expected price decrease for generic tolterodine ER in Finland.

CONCLUSION

Fesoterodine is cost effective or cost saving relative to tolterodine ER for the treatment of OAB with UUI in two European countries. Payers and prescribers should consider a broad scope of costs to make informed cost-conscious choices of antimuscarinic treatment.

Treatment satisfaction and improvement in health-related quality of life with onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity

AIMS

OnabotulinumtoxinA significantly reduces urinary incontinence (UI) and improves bladder management in patients with neurogenic detrusor overactivity (NDO). We evaluated the impact of onabotulinumtoxinA on patient-reported outcomes (PROs) in patients with UI due to NDO in a double-blind, placebo-controlled study.

METHODS

Patients with UI due to NDO (from multiple sclerosis or spinal cord injury) were randomized to intradetrusor placebo (n = 92) or onabotulinumtoxinA 200 U (n = 92) or 300 U (n = 91). PROs included Incontinence Quality of Life (I-QOL) Questionnaire to assess health-related quality of life (HRQoL), the 16-item modified Overactive Bladder-Patient Satisfaction with Treatment Questionnaire (OAB-PSTQ) to assess treatment satisfaction, and Patient Global Assessment to assess treatment goal achievement.

RESULTS

Mean improvement in I-QOL total score at weeks 6 and 12 was significantly greater with both onabotulinumtoxinA 200 U and 300 U versus placebo (Δ12.3 for 200 U and Δ14.9 for 300 U vs. placebo; P < 0.001), and was clinically meaningful. For those patients who completed the OAB-PSTQ, improvement in satisfaction at weeks 6 and 12 was significantly greater for onabotulinumtoxinA versus placebo (P < 0.001, all comparisons). At 6 weeks, greater proportions of onabotulinumtoxinA-treated patients than placebo reported being somewhat or very satisfied (200 U, 77.5% and 300 U, 67.8% vs. placebo, 39.5%), and significant progress toward or complete achievement of primary treatment goal (200 U, 62.9% and 300 U, 61.6% vs. placebo, 16.5%).

CONCLUSIONS

NDO patients treated with onabotulinumtoxinA 200 or 300 U had significantly greater improvement in HRQoL and greater treatment satisfaction compared with placebo-treated patients, with no clinically relevant differences between onabotulinumtoxinA doses.

Phase IIb, multicenter, double-blind, randomized, placebo-controlled, parallel-group study to determine effects of elocalcitol in women with overactive bladder and idiopathic detrusor overactivity

OBJECTIVE

To evaluate the efficacy and safety of elocalcitol in the treatment of women with overactive bladder and idiopathic detrusor overactivity.

METHODS

The study was a multicenter, double-blind, randomized, placebo-controlled, parallel-group trial of women with overactive bladder symptoms recruited from 48 European tertiary referral centers. The participants were randomized to receive either placebo or elocalcitol, 75 μg/d or 150 μg/d for 4 weeks. A 3-day bladder diary, the Urgency Perception Scale, the Patient's Perception of Bladder Condition, and urodynamics were used before and after treatment. Vital signs, laboratory blood tests, 24-hour urine collection, and electrocardiography were also performed to assess the safety. The analysis of covariance test was used to compare the treatment groups. The primary objective was to evaluate the change in bladder volume at the first involuntary detrusor contraction from baseline.

RESULTS

A total of 308 women were studied. No significant change was seen in the urodynamic parameters between the placebo and elocalcitol groups, except for the bladder volume at the first desire to void. The frequency of incontinence episodes was significantly reduced in the elocalcitol group compared with the placebo group (P = .02). The Patient's Perception of Bladder Condition score improved significantly after treatment for the women receiving elocalcitol compared with those receiving placebo (P = .02). Treatment with both doses of elocalcitol was well tolerated, and no differences versus placebo were observed.

CONCLUSION

Although the primary endpoint was not achieved, elocalcitol appears to be an effective and well-tolerated drug for the treatment of women with overactive bladder and idiopathic detrusor overactivity. However, the multicenter setting for the use of urodynamics might have biased the results of our study.

Efficacy and safety of onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Neurogenic detrusor overactivity (NDO) frequently results in urinary incontinence (UI) which impairs quality of life (QOL) and puts the upper urinary tract at risk.

OBJECTIVE

To assess the effects of onabotulinumtoxinA (BOTOX(®), Allergan, Inc.) on UI, urodynamic variables, and QOL in incontinent patients with NDO.

DESIGN, SETTING, AND PARTICIPANTS

This multicentre, randomised, double-blind, placebo-controlled study enrolled patients with multiple sclerosis (MS; n=154) or spinal cord injury (SCI; n=121) with UI due to NDO (≥14 UI episodes per week).

INTERVENTION

Patients received 30 intradetrusor injections of onabotulinumtoxinA 200 U (n=92), 300 U (n=91), or placebo (n=92), avoiding the trigone.

MEASUREMENTS

Primary end point was change from baseline in UI episodes per week (week 6). Secondary end points included urodynamics (maximum cystometric capacity [MCC], maximum detrusor pressure during first involuntary detrusor contraction [P(detmaxIDC)]), and Incontinence Quality of Life (I-QOL) total score. Adverse events (AEs) were assessed.

RESULTS AND LIMITATIONS

At baseline, mean UI episodes per week (33.5) were similar across groups. At week 6, onabotulinumtoxinA 200 U and 300 U significantly reduced UI episodes per week (-21.8 and -19.4, respectively) compared with placebo (-13.2; p<0.01); onabotulinumtoxinA benefit was observed by the first posttreatment study visit at week 2. Improvements in MCC, P(detmaxIDC), and I-QOL at week 6 were significantly greater with both onabotulinumtoxinA doses than with placebo (p<0.001). Benefits were observed in both the MS and SCI populations. The median time to patient request for retreatment was the same for both onabotulinumtoxinA doses (42.1 wk) and greater than placebo (13.1 wk; p<0.001). Most frequent AEs were localised urologic events (urinary tract infections and urinary retention, which were dose related in patients not using clean intermittent catheterisation [CIC] at baseline). Significant increases in postvoid residual were observed in patients not using CIC prior to treatment, and 12%, 30%, and 42% of patients in the placebo, 200-U, and 300-U groups, respectively, initiated CIC posttreatment.

CONCLUSIONS

OnabotulinumtoxinA significantly reduced UI and improved urodynamics and QOL in MS and SCI patients with NDO. Both doses were well tolerated with no clinically relevant differences in efficacy or duration of effect between the two doses (http://www.clinicaltrials.gov; NCT00461292).