The effect of intravesical sodium nitroprusside on idiopathic detrusor overactivity

Although nitric oxide (NO) plays an important role in the urethra and outlet region of the bladder, the role of this inhibitory neurotransmitter in the human detrusor remains unclear. We conducted a prospective, randomised, open study on 31 patients with urodynamically proven idiopathic detrusor overactivity in order to examine the effects of intravesical administration of the NO donor sodium nitroprusside (SNP) on detrusor overactivity. Thirty-one consecutive patients (14 male, 17 female; mean age 53.0±2.7 years) with idiopathic detrusor overactivity diagnosed by pressure-flow analysis were included in this study. The patients were randomised into two groups. Cystometries were performed with normal saline in the control group (n=10) and with 7.2 mM SNP solution (2.16 mg/ml) in the study group (n=21). We urodynamically investigated sensation, maximal cystometric capacity, compliance, instability index, amplitude and frequency of involuntary contractions. No statistically significant differences was found between the first (pressure-flow) and second (saline or SNP cystometry) urodynamic values in the control and study groups (P>0.05). We have demonstrated that SNP does not have any effect on uninhibited bladder contractions. These results suggest that the intravesical administration of SNP is not an effective treatment for detrusor overactivity.