A Role of Intravesical Capsaicin Instillation in Benign Prostatic Hyperplasia with Overactive Bladder Symptoms: The First Reported Study in the Literature
Phitsanu Mahawong MD*, Bansithi Chaiyaprasithi MD*, Suchai Soontrapa MD*, Pimolvan Tappayuthapijarn MS**
Affiliation : * Division of Urology, Department of Surgery, Faculty of Medicine, Siriraj Hospital, Mahidol University ** Department of Pharmacology, Faculty of Medicine, Siriraj Hospital, Mahidol University
Objective : To study the efficacy of capsaicin in treating overactive bladder symptoms in benign prostatic
hyperplasia patients.
Materials and Methods : A prospective study of 20 benign prostatic hyperplasia patients whose overactive
bladder symptoms were not improved by alpha1 blocker. Alpha1 blocker was taken about 22.9 + 17.2 months
before and continued throughout 6 months duration of the present study. All of them had undergone intravesi-
cal capsaicin instillation at the Faculty of Medicine Siriraj Hospital, Bangkok, from 2004 to 2006. Both
clinical and urodynamic data were evaluated before and after treatment.
Results : Mean urgency decreased from 6.7 + 5.1 at baseline to 2.0 + 2.3 (p < 0.005), 1.4 + 2.4 (p < 0.005), 1.3
+ 2.2 (p < 0.005) at 1, 3 and 6 months. Mean urge incontinence decreased from 1.7 + 3.5 at baseline to 0.5 +
1.3 (p = 0.148), 0.4 + 1.2 (p = 0.114), 0.3 + 1.1 (p = 0.085) at 1, 3 and 6 months. Mean urinary frequency
decreased from 13.7 + 3.3 at baseline to 10.5 + 2.8 (p < 0.005), 9.6 + 2.0 (p < 0.005), 9.5 + 2.6 (p < 0.005) at
1, 3 and 6 months. Mean nocturia decreased from 4.7 + 2.4 at baseline to 3.1 + 2.2 (p < 0.005), 2.7 + 1.2 (p <
0.005), 2.9 + 1.6 (p < 0.005) at 1, 3 and 6 months. Mean first desire to void increased from 172.5 + 100.4 ml at
baseline to 210.6 + 99.5 ml (p = 0.016) at 1 month. Mean maximal cystometric capacity increased from 350.3
+ 165.9 ml at baseline to 397.4 + 165.7 ml (p = 0.012) at 1 month. Peak flow rate, detrusor pressure, and
postvoid residual urine were not affected. No serious adverse effect occurred in the present study.
Conclusion : Intravesical capsaicin instillation is an effective treatment for overactive bladder symptoms in
benign prostatic hyperplasia patients.
Keywords : Capsaicin, Benign prostatic hyperplasia, Overactive bladder
