Editorial: Is botulinum toxin not the solution to OAB after all?
Dirk De Ridder
Department of Urology, University Hospital Leuven, Belgium
The article by Mohee et al. highlights a problem that is often neglected: the outomes we see in clinical trials do not predict the success of the therapy in real life. We know this from anticholinergics: the study results are good, but the performance in real life is much poorer. Only 20-40% will continue to take the medication.
For botulinum toxin in OAB it is surprising to see that even in experienced hands only 38.7% of patients continued with the treatment at 36 months. The reasons to abandon the treatment were retention, the need for CISC and urinary tract infections. Moreover, 8.6% of the patients had no response at all after the initial injection.
Of course infections could have been avoided by using prophylactic antibiotics, but the other issues remain. How to explain the primary failures? How to manage the risk of CISC?
Given the fact that most patients abandoned the treatment within the first 3 years, more research would be needed on how to increase the treatment adherence of the patients after the initial injection.
This challenging article also stresses the fact that in a time where only RCTs stand a good chance of being published in journals, good retrospective cohort studies can be extremely important too.
What a wonderful state of the art lecture from Dirk at the BAUS/SARS meeting in London yesterday. The search for a better treatment for IDO continues. The underpinning science is Biomarker discovery in OAB but it seems that we are not making progress in the right direction. The initial enthusiasm with NGF is tempered by widely variant results. Perhaps advanced imaging of small animal models of OAB will provide better answers but again translation to humans is not necessarily guaranteed. It seems that prospectively evaluating new therapies such as Onabotulinumtoxin A should continue in parallel with the search for new Biomarkers.
Great article, thanks for putting this up.
Two questions for bloggers:
1. How useful does everyone find urodynamic studies in predicting those who would benefit from botox? I do it routinely, but can it predict responders vs non responders? I find it useful to rule out other conditions especially primary obstruction that was not picked up clinically and may be more likely to predispose someone to retention.
2. This article uses 200 units and 300 units of botox for idiopathic DO. Does anyone else use lower doses? I prefer starting with 100 units for this group, less risk of retention and my feeling is that it is better tolerated. What would everyone else do?
Dear Conrad
I use 100 U for idiopathic OAB too. I find urodynamics not predictive of the results. I am not sure that urodynamics can predict obstruction and retention, especially in women.