[Trospium chloride once daily for overactive bladder syndrome: results of a multicenter observational study].

BACKGROUND: An extended release form of trospium chloride (Urivesc 60 mg® slow release capsules) was recently approved for the treatment of overactive bladder syndrome (OAB). A multicentric, prospective observational study was conducted under routine private practice conditions to assess the safety and efficacy of this treatment in this indication, as well as the effect on quality of life parameters. PATIENTS AND METHODS: A total of 305 patients with OAB syndrome (mean age 60 years, 79% females) were evaluated in this prospective, non-interventional observation study. All patients received trospium chloride once daily (Urivesc® 60 mg extended release capsules) in accordance with the approved prescribing instructions. At the start of therapy and after a treatment period of 4 and 13 weeks (median) the patient urological endpoints and quality of life parameters were assessed. Safety and tolerability were evaluated from the documentation of all adverse events occurring during the entire observation period.
RESULTS: Mean daily frequency of micturition decreased over the treatment period with once daily trospium chloride from 11.7 ± 4.3 to 7.7 ± 2.9 per 24 h (p<0.0001). In parallel the mean individual urine volume voided increased from 169.3 ± 79.8 ml to 238.4 ± 122.0 ml (p<0.0001). The proportion of patients with incontinence fell from 36.7% at the initiation of therapy to 20.3% at the end of therapy. Furthermore, the mean number of incontinence pads used declined from 3 per day to 1 per day. More than one third of initially incontinent patients (39.3%) needed no incontinence pads at the end of the treatment period. Quality of life parameters improved significantly in all five subsections recorded (i.e. daily life, family life, sleep quality, self esteem and ability to travel). The safety and tolerability of Urivesc 60 mg extended release was good, with a particularly low incidence of mouth dryness (1% of patients) reported. No central nervous system (CNS) associated adverse events and no serious adverse events occurred.
CONCLUSION: As a once daily formulation prescribed under normal private practice conditions, the new trospium chloride extended-release formulation consistently demonstrated efficacy and tolerability for treatment of OBS. Treatment with once daily trospium chloride 60 mg extended release capsules significantly improved the frequency of micturition and nocturia, as well as incontinence episodes and use of absorptive pads in this patient population, accompanied by an improvement in quality of life. The reason for the good tolerability, in particular the relatively low incidence of mouth dryness, is probably due to the lower peak plasma concentration of trospium (cmax) enabled by the modified-release galenical form employed by the 60 mg extended release formulation. Once daily administration enabled enhanced compliance for the modified release formulation and associated improved tolerability. The limited access of trospium to the CNS afforded by the intact blood-brain barrier and absence of metabolic interaction potential via cytochrome P450 are established characteristics of trospium chloride. This infers a lower potential to impair cognitive function and a lower potential for metabolic interactions with concomitant medications. In the context of elderly patients and multimorbid and polypharmacy scenarios, the sum of these characteristics may afford distinct advantages in treating OAB patients.