New developments in the treatment of urinary incontinence

Urinary incontinence is a common and distressing condition. The two main types of incontinence in the developed world are urodynamic stress incontinence and detrusor overactivity. Recent advances have focussed on the development of a drug for stress incontinence and on the production of newer more M3 specific anticholinergics. Duloxetine, a relatively balanced and potent serotonin noradrenaline reuptake inhibitor, is the first drug to be licensed for stress incontinence. Until recently, the pharmacological treatment options for stress urinary incontinence (SUI) have been limited to the off-the label use of several medications including oestrogens, alfa adrenergic receptor agonists, beta adrenergic receptor antagonists, tricyclic antidepressants and anticholinergics. However, these medications have questionable efficacy which may be associated with adverse effects. Randomised trials have shown duloxetine to be effective at reducing incontinence episode frequency and improving quality of life scores. Hence medical management has now become a more realistic option for treatment of patients with sui. Recently newer more M3 receptor selective anticholinergics have come on to the market. Their increased bladder receptor selectivity implies that they have improved efficacy with a lower side effect profile. Both solifenacin and more recently darifenacin have been marketed and have the above described properties. The oxybutynin patch is now also available adding a new route of delivery. Because it is absorbed transdermally, its manufacturers claim it also has a better efficacy/tolerability ratio then conventional oxybutynin. This review article gives a detailed description of these new pharmacologic developments.