Efficacy of Daily Low-dose Tadalafil for Treating Overactive Bladder: Results of a Randomized, Double-blind, Placebo-controlled Trial.

OBJECTIVE: To evaluate the efficacy of daily low-dose tadalafil therapy for overactive bladder (OAB) in women.

PATIENTS AND METHODS: A total of 96 women with idiopathic OAB from 3 medical centers in the south of Zhejiang Province of China were randomly assigned to treatment with daily low-dose tadalafil (5 mg, n = 48) or placebo (n = 48) for 3 months. The Indevus Urgency Severity Scale, overactive bladder symptom score (Homma et al, 2006), and a 3-day micturition diary with frequency, incontinence, and urgency episodes were recorded and compared before the treatment, every 2 weeks following the treatment, and 3 months after the treatment. Uroflowmetry and transabdominal ultrasound were also conducted following the treatment to determine the maximum flow rate, voided volume, postvoid residual volume, total bladder capacity, and voiding efficiency. The patient's overall rating of improvement in symptoms was assessed as well.

RESULTS: The overactive bladder symptom score significantly decreased, and the frequency, incontinence, and urgency episodes significantly improved in the tadalafil treatment group as compared with the placebo group and baselines at weeks 4, 6, 8, 10, and 12, as well as 3 months posttreatment (P <.05). In addition, voided volume and total bladder capacity obviously increased in the treatment group (P <.05). The Indevus Urgency Severity Scale decreased from week 4 to 3 months posttreatment in the treatment group (P <.05). No changes were found in the maximum flow rate, postvoid residual volume, and voiding efficiency. All adverse symptoms were mild to moderate.

CONCLUSION: Daily low-dose tadalafil is a considerable, well-tolerated, and effective treatment for OAB in women.