Intravesical Botulinum Toxin Injection for Overactive Bladder—What We Can Learn From Previous Clinical Trials

Abstract 

Intravesical botulinum toxin A (BoNT-A) injection is effective in treating overactive bladder (OAB) and detrusor overactivity (DO)-induced incontinence refractory to antimuscarinic treatment. In the past 5 years, there have been several clinical trials using BoNT-A targeting OAB and idiopathic DO (IDO), and the therapeutic results are promising. Recent investigations have shown that urothelial dysfunction and abnormality of sensory receptor expression or transmitter release in the suburothelial nerves might contribute to OAB refractory to antimuscarinics. Intravesical BoNT-A treatment to inhibit abnormal receptor expression or transmitter release in the sensory nerve terminals in the suburothelial space has shown to have a good therapeutic effect on OAB. Intradetrusor or suburothelial BoNT-A injections, with small or large doses of BoNT-A in the bladder body or bladder base, can achieve satisfactory results. However, BoNT-A impairs detrusor contractility and causes a large postvoid residual (PVR) urine volume after injection in some patients. This adverse effect induces acute urinary retention and it is difficult to empty the bladder in the early postoperative period. Urinary tract infections can occur in patients with a large PVR. Although adverse effects may not influence the therapeutic outcome, they might prohibit wide application of BoNT-A in the treatment of refractory OAB. Patients with a high risk of a large PVR or urinary retention should be taught clean intermittent catheterization. Analysis of patient characteristics and urodynamic variables has shown that patients who are elderly, have low detrusor contractility at baseline, and have chronic medical diseases are at risk of adverse effects. Therefore, careful adjustment of the dose, appropriate injection site and correct patient selection is mandatory to achieve satisfactory results with intravesical BoNT-A therapy.

Keywords:  Adverse event , Botulinum toxin , Intravesical treatment , Overactive bladder , Urodynamics

No full text is available. To read the body of this article, please view the PDF online.