Overactive bladder (OAB) is defined as "urgency, with or without urge incontinence, usually with frequency and nocturia" in the absence of local pathological or endocrine factors. Urgency is defined as "the complaint of a sudden compelling desire to pass urine that is difficult to defer" and an abnormal sensation that is distinctly different from the normal physiologic feeling of 'urge to void' that occurs during typical bladder-filling cycles.

Because up to 50% of patients with OAB experience urgency without incontinence, and because urgency is the most bothersome symptom that drives behavioral adaptations such as frequent voiding because of the very fear of urgency, this is the cornerstone symptom of OAB that indicates the diagnosis of OAB.

Even though any effective treatment for OAB must reduce the patient's sense of urgency, its subjective nature makes it difficult to measure. Therefore, the clinical efficacy of OAB treatment was traditionally measured in terms of objective surrogate parameters instead of urgency itself: for example, change in urinary frequency, incontinent episodes, number of pads and urodynamically proven detrusor overactivity, which could be measured easily and quantifiably.

Recently, several methods that measure urgency have been developed and used in clinical practice. However, the analysis questioned the clinical significance of the results; a possible reason for this being the lack of data based on urinary urgency and the use of sensitive patient-driven criteria.

Propiverine hydrochloride (1-methyl-4-piperidyl diphenylpropoxyacetate hydrochloride) is a drug with combined antimuscarinic and calcium antagonistic actions. Previous trials on the clinical efficacy and safety of propiverine for treating patients with OAB have reported improvements in urinary frequency and incontinence, but not in urgency.

The aim of this study was to explore the efficacy of a daily regimen of propiverine at 20 mg (immediate release formulation) in improving urgency from baseline to 12 weeks of treatment in patients with OAB.

12-week multi-center, prospective, parallel, double-blind, placebo-controlled trial

Inclusion Criteria:

• age ≥ 18 years

• Overactive bladder for at least 3 months

• 3 day- voiding diary

  • average urinary frequency ≥ 10 voids/24hrs
  • urgency ≥ 2 episodes/24hrs

• "moderate to severe" in the Indevus Urgency Severity Scale (IUSS)

Exclusion Criteria:

• clinically significant stress urinary incontinence
• polyuria of more than 3000 ml/24 hrs
• severe hepatic or renal diseases
• contraindications to the use of antimuscarinic drugs
• genitourinary conditions that could cause OAB symptoms such as urinary tract infection, genitourinary malignancy or interstitial cystitis
• uninvestigated hematuria
• clinically significant bladder outlet obstruction
• clinically significant pelvic organ prolapse
• being on a bladder-training program or having been on electrostimulation therapy two weeks before randomization or intention to start
• unstable dosages of drugs with anticholinergic side effects
• any other investigational drug taken up to 2 months prior to randomization
• pregnancy or breastfeeding