The term “overactive bladder” was proposed as a way of approaching the clinical problem from a symptomatic rather than a urodynamic perspective. The overactive bladder syndrome (OAB) has been defined by the International Continence Society as urinary urgency with or without urge incontinence usually with frequency and nocturia. It is a diagnosis based on lower urinary tract symptoms alone. While not life threatening, it can have a considerable adverse impact on the quality of lives of those who suffer from it, and it is highly prevalent within society. Recent epidemiological studies have reported the overall prevalence of OAB in women to be 16%, suggesting that there could be 17.5 million women in the USA who suffer from the condition. The prevalence increases with increasing age being 4 percent in women younger than 25 years and 30 percent in those older than 65 years. The overall prevalence of OAB in individuals aged 40 years and older is 16%. Frequency, the most common symptom, occurs in 85% of respondents, while 54% complain of urgency and 36% of urge incontinence.
Initial management of OAB should take into account the individual’s lifestyle and any appropriate interventions that can be employed to minimize symptoms. For example, reducing excessive fluid intake (25ml / kg / day is sufficient) and minimising caffeine and alcohol consumption may be helpful, as well as reviewing any medication that may have an impact on lower urinary tract function, such as diuretics.
Behavioral therapies and, particular, bladder retraining may help a person regain central control of micturition and can be highly effective in well – motivated individuals, although there is a recognized high relapse rate.
Drug therapy is the mainstay of treatment for OAB, and from the number of preparations that have been studied, it is clear that there is no ideal drug for all people. In the past, clinical results of treatment have often been disappointing due to both to poor efficacy and unacceptable adverse effects. Earlier preparations were not subjected to the current rigorous randomised controlled trials and, therefore, lack evidence – based data. Comparison of drug therapies for this condition is difficult due to the placebo effect of 30 – 40%, and since the response to any of the available drugs is only in the region of 60%, any differences that are detected are likely to be small, and thus require large – scale studies to show efficacy.
The drugs that are currently prescribed for OAB have an antimuscarinic component, and this limits compliance with the treatment because of a lack of acceptability to some people. Recent advances have included sustained release preparations of existing compounds, innovative routes of administration and newer antimuscarinic preparations.
While many people will be considerably improved and even cured of their symptoms by drug therapy, there are always those who do not respond and for them, it is most important that further investigations are undertaken to ensure that the correct problem is being addressed. Urodynamic studies will confirm (or otherwise) a diagnosis of detrusor overactivity in which case, further trials of different antimuscarinic preparations would be desirable, whereas in the absence of proven detrusor overactivity, an alternative diagnosis should be sought to avoid further ineffectual treatment and, hence disillusionment and a waste of resources.