Solifenacin Plus Tamsulosin Combination Treatment in Men With Lower Urinary Tract Symptoms and Bladder Outlet Obstruction: A Randomized Controlled Trial

BackgroundAlpha blockers are prescribed to manage lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Antimuscarinics are prescribed to treat overactive bladder (OAB).ObjectiveTo investigate the safety of a combination of solifenacin (SOLI) and tamsulosin oral controlled absorption system (TOCAS) in men with LUTS and bladder outlet obstruction (BOO).Design, setting, and participantsRandomized, double-blind, parallel-group, placebo-controlled study in men aged >45 yr with LUTS and BOO for ≥3 mo, total International Prostate Symptom Score (IPSS) ≥8, BOO index ≥20, maximum urinary flow rate (Qmax) ≤12 ml/s, and voided volume ≥120 ml.InterventionsOnce-daily coadministration of TOCAS 0.4 mg plus SOLI 6 mg, TOCAS 0.4 mg plus SOLI 9 mg, or placebo for 12 wk.Outcome measurements and statistical analysisPrimary (safety) measurements: Qmax and detrusor pressure at Qmax (PdetQmax). Other safety assessments included postvoid residual (PVR) volume. Secondary end points included bladder contractile index (BCI) score and percent bladder voiding efficiency (BVE). An analysis of covariance model compared each TOCAS plus SOLI combination with placebo.Results and limitationsBoth active treatment groups were noninferior to placebo at end of treatment (EOT) for PdetQmax and Qmax. Mean change from baseline PVR was significantly higher at all time points for TOCAS 0.4 mg plus SOLI 6 mg, and at weeks 2, 12, and EOT for TOCAS 0.4 mg plus SOLI 9 mg versus placebo. Both treatment groups were similar to placebo for BCI and BVE. Urinary retention was seen in only one patient receiving TOCAS 0.4 mg plus SOLI 6 mg. Limitations of the study were that prostate size and prostate-specific antigen level were not measured.ConclusionsTOCAS 0.4 mg plus SOLI 6 mg or 9 mg was noninferior to placebo at EOT for PdetQmax and Qmax in men with LUTS and BOO, and there was no clinical or statistical evidence of increased risk of urinary retention.