Duloxetine for the treatment of overactive bladder syndrome in multiple sclerosis: a pilot study

Overactive bladder (OAB) syndrome represents one of the main urinary disorders associated with multiple sclerosis (MS). At present, no widely accepted effective treatment is available. Duloxetine, an antidepressant acting as a selective serotonin-norepinephrine reuptake inhibitor, has been shown to be effective in the treatment of some symptoms of stress urinary incontinence and OAB because of etiology other than MS.The present study aims at establishing the efficacy and tolerability of duloxetine in the treatment of OAB in patients affected by remitting-relapsing MS and secondary progressive MS.

Twenty-three patients with MS, 13 of which with remitting-relapsing MS and 10 with secondary progressive MS, have been treated with duloxetine and placebo for a total period of 8 weeks during a single-blinded cross-over trial. At each programmed visit, patients have been screened for the following: (1) quantitative evaluation of maximal bladder capacity and postmicturition residual volume; (2) questionnaire administration to evaluate bladder disorder--Overactive Bladder Questionnaire, quality of life--Visual Analogue Scale-Quality of life, fatigue--Fatigue Severity Scale, and depression--Beck Depression Inventory.

Three patients did not complete the study because of duloxetine-related adverse events. A statistically significant improvement in bladder disorder, as measured by OAB-Q, has been observed after duloxetine treatment compared with both basal levels and placebo with values of 21.8 ± 1.1 versus 34.2 ± 1.2 (P < 0.0001) and 21.8 ± 1.1 versus 30.1 ± 1.7 (P < 0.003), respectively.In addition, a decrease in postmicturition residual volume has also been observed compared with basal level (6.8 ± 3.2 ml vs 38.1 ± 12.2 ml, P = 0.06) together with an improvement in quality of life (7.1 ± 0.5 vs 6.3 ± 0.4, P = 0.07). Both these changes were close to being statistically significant.

It emerges from this study that duloxetine might become an effective therapeutic alternative to be investigated in a larger number of MS patients for the treatment of OAB. Duloxetine should be considered a first-choice drug in the treatment of MS patients presenting both depression and OAB; in addition, it should also be considered as a suitable alternative or as concomitant treatment in MS patients with OAB but not experiencing depression.