Current diagnostics and therapy of the overactive bladder and urge incontinence

Urinary incontinence affects millions of people worldwide and also represents a social problem. Costs of urinary incontinence and overactive bladder are very high. Urge incontinence is the involuntary loss of urine associated with a strong desire or urge to urinate. There are two types of urge incontinence: One is associated with involuntary detrusor contractions leading to a loss of urine, the other is characterized by a hypersensitive bladder in which micturition reflexes are induced due to an increased afferent activity. It is important to distinguish between an idiopathic type of urge incontinence and a symptomatic type possibly caused by infections, tumours, bladder stones or foreign bodies. Diagnostics is based on a careful medical history, clinical examination and urodynamic evaluation. The use of a voiding diary is necessary. Current agents for drug therapy rely upon their anticholinergic properties. Their use is limited by side effects such as blurred vision, dizziness, constipation and dryness of the mouth. Additionally, patients refractory to anticholinergic medication can be treated by endoscopic direct injection of botulinum toxin into the detrusor muscle. These patients can also be treated by intravesical application of vanilloid derivatives in the bladder leading to a desensitization of bladder sensory fibers. In some cases of refractory urge incontinence, electrical neuromodulation is effective. Other pharmacological approaches could be selective b-adrenoceptor agonists, calcium antagonists and potassium channel openers, but these substances are not yet available for clinical use.