Human urine with solifenacin intake but not tolterodine or darifenacin intake blocks detrusor overactivity.

The objective of the study was to evaluate the local effects of three antimuscarinics excreted into human urine after oral ingestion. Two normal adult collected their voided urine after taking oral doses of tolterodine, darifenacin, and solifenacin for 7 days with a 14-day washout period. The urodynamic effect of intravesically administered human urine on carbachol-induced bladder overactivity was studied in female rats. Cystometric parameters were measured during continuous infusion of saline and human urine and then a mixture of carbachol (30 microM) and human urine. Carbachol significantly reduced the intercontraction interval and bladder capacity in the control (urine taken in the absence of oral antimuscarinics) and tolterodine- or darifenacin-administered groups. However, human urine obtained after taking solifenacin prevented the carbachol-induced detrusor overactivity. Urine excreted after oral ingestion of solifenacin provides a localized pharmacological advantage for the treatment of the overactive bladder syndrome.