Investigation of the clinical efficacy and safety of pregabalin alone or combined with tolterodine in female subjects with idiopathic overactive bladder.

Aims: To assess the efficacy and safety of pregabalin alone or in combination with tolterodine extended release (ER) in subjects with idiopathic OAB.

Methods: This 26-week, multicenter, randomized, double-blind, placebo-controlled, three-period crossover study enrolled women aged ≥ 18 years that were diagnosed with OAB and reported ≥ 8 micturitions/24 hr and ≥ 4 urgency episodes/week on 5-day bladder diary at baseline. Subjects were randomized to 1 of 10 treatment sequences and received three of five treatments, each for 4 weeks with 4-week washout periods: standard-dose pregabalin/tolterodine ER (150 mg twice daily [BID]/4 mg once daily [QD], n=102), pregabalin alone (150 mg BID, n=105), tolterodine ER alone (4 mg QD, n=104), low-dose pregabalin/tolterodine ER (75 mg BID/2 mg QD, n=105), and placebo (n=103). Subjects completed 5-day diaries at the end of treatment and washout periods. The primary endpoint was change from baseline to week 4 in mean voided volume (MVV) per micturition. The primary comparison was standard-dose pregabalin/tolterodine ER versus tolterodine ER alone; secondary comparisons were pregabalin alone versus tolterodine ER alone and versus placebo.

Results: Baseline-adjusted changes in MVV were significantly greater after treatment with standard-dose pregabalin/tolterodine ER (39.5 ml) versus tolterodine ER alone (15.5 ml; P<0.0001), and with pregabalin alone (27.4 ml) versus tolterodine ER alone (P=0.005) and placebo (11.9 ml; P=0.0006). Treatments were generally well tolerated; discontinuation rates due to adverse events were 4%, 2%, 5%, 0%, and 1% with standard- and low-dose pregabalin/tolterodine ER, pregabalin, tolterodine ER, and placebo, respectively.

Conclusions: Pregabalin, alone or with tolterodine ER may offer an alternative treatment option for idiopathic OAB in women.