Duloxetine in the treatment of stress urinary incontinence.

Stress urinary incontinence (SUI) is the most common form of urinary incontinence and occurs more frequently in women than in men. Duloxetine is a balanced dual serotonin (5-HT) and norepinephrine (NE) reuptake inhibitor and shows no relevant binding affinity for histaminergic, dopaminergic, cholinergic, and adrenergic receptors. The efficacy of duloxetine in SUI is based on the inhibition of the presynaptic reuptake of 5-HT and NE in Onuf's nucleus of the sacral spinal cord, whereby it may increase the concentration of 5-HT and NE in the synaptic cleft. The effectiveness of duloxetine was studied in a cat model of acetic acid-induced bladder irritation. The results showed that in cats with previous irritated bladder function, there was a dosage-dependent improvement of bladder capacity and periurethral electromyography (EMG) activity. In women with SUI, it is assumed that the clinical efficacy of duloxetine is based on stronger urethral contraction and persistent sphincter tone during the storage phase. In clinical trials in women with SUI, duloxetine has demonstrated efficacy in reducing incontinence episodes and increasing quality of life. Nausea was the most common adverse event and the main cause for discontinuation. In summary, duloxetine appears to be a promising new option for the treatment of SUI.