Comparsion of the histologic and urodynamic effects of anticholinergic drugs such as oxybutynin, tolterodine and trospium chloride on the bladder

Oral anticholinergic drugs has been used extensively and effectively in the management of overactive bladder, interstitial cystitis, urinary incontinence and neurogenic bladder. However, the usefulness of these drugs is often limited by intolerable systemic anticholinergic side effects such as dry mouth, blurred vision, somnolance, constipation and increased heart rate. Intravesically applied oxybutynin ,has been reported to have no significant systemic anticholinergic side effects, based on clinical studies from both children and adults. But the histologic effects of these drugs on the bladder is not well established. We aimed to compare the histologic and urodynamic effects of these drugs on the bladder.Twenty New Zeland White male rabbits, five in each groups (control, oxybutynin, tolterodine, trospium chloride), were used for this study. They were catheterized daily and intravesical solutions instilled for as long as 30 days. Bladder capacity were measured urodynamically before and after study. Then the bladder were analyzed histologically under light microscope.We found series inflamatuar changes and epithelial destruction in tolterodine and trospium chloride groups. No histologic changes found in control group but, a mild subepitelyal inflammation has been found in oxybutynin group comperable with control group. We didn?t find statisticaly significant changes on bladder capacity in any groups.Intravesical oxybutynin found to be locally safe. However, consideration should be given to the use of intravesical tolterodine and trospium chloride, since these two drugs may lead to series local tissue inflammation.