Onabotulinum toxin a (botox®) in the treatment of neurogenic bladder overactivity

Botulinum toxin (BT) is a potent presynaptic neuromuscular blocking agent which induces selective, reversible muscle weakness for months when injected intramuscularly. During recent years BT has revolutionized the treatment of previously intractable symptoms of detrusor overactivity. Based on a systematic search of the PubMed database, a review of the current literature on the use of onabotulinum toxin A (Botox®) in the treatment of neurogenic detrusor overactivity is presented. Onabotulinum toxin A proved to be highly effective in the majority of studies, even though a wide range of injection techniques and dosages were described. The onset of the effect usually appeared before 2 weeks, and reached a peak within 2-6 weeks, with the clinical effect being maintained for approximately 6-8 months, or even longer. Depending on the dose, a number of patients developed high residual volume and clean intermittent self/helper catheterization (CIC) may become necessary. Only a few side effects were described, and intravesical onabotulinum toxin A injection seems to be well tolerated. However, details on injection technique, dose interval between injections, etc. are still under debate and only a few randomized, placebo controlled studies have been published.