Adverse events after botulinum A toxin injection for neurogenic voiding disorders.

OBJECTIVES: To review the side effects of local injections of botulinum A toxin (BTX-A). METHODS: A medline search for publications about adverse events after injection of BTX-A for lower urinary tract dysfunctions. RESULTS: We found four publications that report generalised side effects after BTX-A injection for detrusor overactivity (two) and detrusor-sphincter dyssynergia (two). The causes of generalised adverse events are not clear, but spread outside the target organ and into the systemic circulation may contribute. The dose used, the injection volume and the injection technique can all play a role. CONCLUSION: Generalised side effects after BTX-A injection for voiding disorders are rare but they can be very disabling for spinal cord-injured patients. Although no long-term side effects are reported so far, urologists should be aware that these effects of BTX-A injections are unknown.