Add-on anticholinergic therapy for residual nocturia in patients with lower urinary tract symptoms receiving α1-blocker treatment: a multi-centre, prospective, randomised study

Purpose To evaluate the efficacy and safety of imidafenacin (IM), a novel short half-life anticholinergic, as add-on therapy for male LUTS with nocturia and nocturnal polyuria. Materials and methods This multicenter, prospective, randomized, open-labelled study was conducted and involved men who had frequency, urgency, and nocturia despite receiving a stable dose of α1-blocker for ≥1 month. Subjects were randomised to control (α1-blocker alone), IM twice/day (α1-blocker +0.1 mg imidafenacin twice daily), or IM nightly (α1-blocker plus 0.1 mg imidafenacin nightly) group; the treatment period was 8 weeks. Primary endpoints included improvements in night-time frequency and Nocturia Quality of Life Questionnaire (N-QOL) scores. Secondary endpoints included changes from the baseline in frequency volume chart variables, and post-void residual volume. Results and limitations Compared with the controls, IM twice/day and IM nightly patients had a significantly lower night-time frequency (changes from baseline: 0.1 ± 0.8 in control, −0.6 ± 0.9 in IM twice/day, and −0.4 ± 1.0 in IM nightly, p = 0.5227, 0.0006 and 0.0143, respectively). The hours of undisturbed sleep and N-QOL score were significantly improved in IM twice/day group, though not IM nightly group. Nocturnal urine volume was significantly reduced in IM nightly group, although total urine volume remained unchanged. Conclusions A short half-life anticholinergic is suggested to be safe and effective as an add-on therapy for residual nocturia in patients with male LUTS receiving α1-blocker treatment. Anticholinergic administration nightly could reduce the nocturnal urine volume.