Cranberry versus placebo in the prevention of urinary infections in multiple sclerosis: a multicenter, randomized,...

Our aim was to assess the usefulness of cranberry extract in multiple sclerosis (MS) patients suffering from urinary disorders.

In total, 171 adult MS outpatients with urinary disorders presenting at eight centers were randomized (stratification according to center and use of clean intermittent self-catheterization) to cranberry versus placebo in a 1-year, prospective, double-blind study that was analyzed using a sequential method on an intent-to-treat basis. An independent monitoring board analyzed the results of the analyses each time 40 patients were assessed on the main endpoint. Cranberry extract (36 mg proanthocyanidins per day) or a matching placebo was taken by participants twice daily for 1 year. The primary endpoint was the time to first symptomatic urinary tract infection (UTI), subject to validation by a validation committee.

The second sequential analyses allowed us to accept the null hypothesis (no difference between cranberry and placebo). There was no difference in time to first symptomatic UTI distribution across 1 year, with an estimated hazard ratio of 0.99, 95% CI [0.61, 1.60] (p = 0.97). Secondary endpoints and tolerance did not differ between groups.

Taking cranberry extract versus placebo twice a day did not prevent UTI occurrence in MS patients with urinary disorders. Trial Registration NCT00280592.