Tadalafil for the treatment of overactive bladder in women
Daily treatment with low-dose tadalafil for overactive bladder appears to be effective and well-tolerated in women, according to a recent study.
Researchers randomized 96 women with idiopathic overactive bladder to receive either low-dose tadalafil (5 mg; n=48) or placebo (n=48) for 3 months.
Efficacy was measured using the Indevus urgency severity scale (IUSS), overactive bladder symptom score (OABSS), and a 3-day micturition diary with frequency, incontinence and urgency episodes. These were recorded and compared at baseline, every 2 weeks following the treatment, and 3 months post-treatment.
Additionally, the maximum flow rate (MFR), voided volume (VV), post-void residual volume (PVR), total bladder capacity (TBC) and voiding efficiency (VE) were assessed using uroflowmetry and transabdominal ultrasound. The overall rating of improvement in symptoms (PORIS) was also evaluated.
Patients in the tadalafil arm showed a significant improvement in OABSS, frequency, incontinence and urgency episodes compared with those in the placebo arm at all time points: weeks 4, 6, 8, 10 and 12, and 3 months post-treatment (p<0.05 for all).
Moreover, tadalafil was associated with a marked increase in VV and TBC, as well as a reduction in IUSS from week 4 to 3 months post-treatment (p<0.05 for all).
MFV, PVR and VE remained unchanged in both treatment arms.
The adverse symptoms were mild to moderate in severity.
Medical management of overactive bladder is targeted at relaxing bladder muscles. In previous studies, PDE5 inhibitors have shown promise in the treatment of lower urinary tract symptoms in older men. PDE5 is observed to have the highest expression in the muscular cells in the lower urinary tract. It affects the cGMP pathway, altering the intracellular calcium concentration—the primary regulator of smooth muscle contractility—as a result. [Asian J Urol 2015;2:33-37]