Objectives: To investigate video-urodynamic effects of mirabegron, a β3 -adrenoceptor agonist, on low-compliance bladder.
Methods: We retrospectively reviewed nine patients (three men, six women, age 17-68 years) who had been diagnosed with lower urinary tract dysfunction with low-compliance bladder, and who underwent video-urodynamic study before and during administration of mirabegron 50 mg once daily. Urodynamic parameters were compared before and after treatment.
Results: Mirabegron treatment significantly increased first desire to void and cystometric capacity with an average increment of 80 mL (P = 0.027) and 123 mL (P = 0.005), respectively. Bladder compliance also significantly increased (mean value 8.1 mL/cmH2 O before, 18.2 mL/cmH2 O after, P = 0.024). In the six patients who had been taking anticholinergic agents at baseline video-urodynamic study and then switched to mirabegron, mean cystometric capacity and bladder compliance were also increased significantly from 208.3 to 346.8 mL (P = 0.015) and from 7.2 to 17.5 mL/cmH2 O (P = 0.047), respectively. Vesicoureteral reflux grade was improved in three of the four patients who had shown vesicoureteral reflux on cystography before treatment.
Conclusions: Mirabegron improves cystometric capacity and bladder compliance, and it lowers vesicoureteral reflux grade in patients with low-compliance bladder. Thus, mirabegron might represent a good alternative drug for low-compliance bladder refractory to anticholinergic treatment.
Keywords: compliance; lower urinary tract dysfunction; mirabegron; urodynamics; vesicoureteral reflux.
© 2015 The Japanese Urological Association.