Exploring New Horizons in Stress Incontinence: the Neurourology Connection

As many as one-third of women are affected by urinary incontinence, the most common of which being stress urinary incontinence (SUI). Incontinence exacts heavy economic and emotional tolls, affecting nearly every aspect of a woman’s life. Fewer than half of women affected by incontinence report the problem to a physician, probably because of embarrassment, low expectations for treatment, and the availability of absorbent products. When a patient does report incontinence to a physician or other healthcare provider, the complaint should be evaluated thoroughly, and include medical and urinary histories, urinary diary, pelvic examination, stress testing, and other basic investigations as indicated. Treatment strategies for SUI include behavior modification, pelvic muscle exercises, and surgery. Success rates for incontinence surgery range between 50% and 85%, but surgery does not meet all patients’ needs. Currently no approved medication exists for treatment of SUI, although off-label use includes alpha-adrenergic agonists, estrogen, and tricyclic antidepressants. Recent findings relative to neurologic regulation of urinary continence have led to development of a new pharmacologic approach to treatment of SUI, based on modulation of neurotransmitters. The first such agent of this type, duloxetine, has demonstrated efficacy with respect to improving incontinence and quality of life in initial clinical trials. (Advanced Studies in Medicine 2002;2(15):541-545) U rinary incontinence (UI) affects as many as 30% of women and has wide-ranging effects on quality of life, affecting social, physical, emotional, and occupational areas of life. Stress incontinence accounts for the majority of overall incontinence prevalence. In normal lower urinary tract function, the bladder and urethra work together to provide for urine storage and micturition. Coordination for these activities comes from the central nervous system through reflexes that communicate with the autonomic and somatic nervous systems via the pelvic, hypogastric, and pudendal nerves and the neurotransmitters acetylcholine and norepinephrine. Treatment strategies for stress urinary incontinence (SUI) include behavioral therapies designed to decrease the magnitude of stress on the bladder, pelvic muscle exercises aimed at increasing urethral resistance, and surgical procedures designed to improve pressure transmission to the urethra. Surgery remains the definitive therapy for SUI, but does not meet all patients’ needs and proves unsuccessful in a substantial number of cases. Currently, no medical therapy is approved by the US Food and Drug Administration (FDA) for the treatment of SUI. Recent advances in the understanding of the neurologic control over bladder function has led to investigation of pharmacologic strategies to improve neurologic function and control of the bladder and urethra. In phase 2 clinical trials, the dual neurotransmitter reuptake inhibitor duloxetine has demonstrated efficacy in SUI, including improved continence and quality of life.