[Efficacy and safety of available therapies in the management of idiopathic overactive bladder: A systematic review of the literature]

Objective: Study the efficacy and adverse events of different pharmacological lines in the treatment of idiopathic overactive bladder (iOAB).

Methods: PubMed research on meta-analyses and randomized controlled trials (RCT) focused on the efficacy and adverse effects of anticholinergics, botulinum toxin and mirabegron since 2005.

Results: Ten meta-analyses of anticholinergics were selected; 16 randomized controlled trials (ERC) comparing botulinum toxin A to either anticholinergic or placebo and 10 ERC studying mirabegron. All the molecules studied showed efficacy compared to placebo in the treatment of iOAB. Anticholinergics remain the first-line pharmacological treatment allowing a significant reduction in the number (nb) of incontinence (-5/week) and in the number of urination (-4/week) as well as a perception of subjective improvement of the symptoms reported by 56 % of the patients treated against 41 % for the placebo group (RR: 1.39 [95 % CI: 1.28-1.51]). The most commonly reported side effect is dry mouth (30 % vs. 8 % in the placebo group). Injections of botulinum toxin A appear to be relatively comparable to anticholinergics in the first line with a decrease in urinary emergency incontinence (UTI) of 3.3/d in the toxin group versus 3.4/d in the anticholinergic group (P=0.81). There was also a higher rate of complete resolution of urinary incontinence in the toxin group (27 % vs. 13 % P=0.03) but significant adverse effects such as lower urinary tract infections (33 % vs. 13 % P>0.01). And the risk of using self-catheterization (5 % vs. 0 % P=0.01). In view of the invasive character of the toxin injections and their side effects, this treatment remains a 2nd line therapy. The same is true for mirabegron: similar efficacy (IUU number in the mirabegron group 50mg -1.74 vs. -1.53 In the solifenacin group 5mg, P>0.5) but different side effects with arterial hypertension (the oral dryness rate being comparable to that in the placebo group). The choice of use of anticholinergic or mirabegron should be based on the balance of efficacy/tolerance to be estimated for each patient.

Conclusion: The different molecules have shown their efficacy in the treatment of iOAB with acceptable tolerance. There is a lack of direct comparisons between treatments available. Further studies are needed to evaluate the possible interest of a combination of these molecules as well as the search for predictive factors of response to these different therapies.