Effect of Low-Dose Triple Therapy Using Gabapentin, Amitriptyline, and a Nonsteroidal Anti-Inflammatory Drug for Overactive Bladder Symptoms in Patients With Bladder Pain Syndrome

PURPOSE Patients with bladder pain syndrome/interstitial cystitis (BPS/IC) can have pain as a main symptom and overactive bladder (OAB) symptoms that are directly or indirectly related to a major mechanism that causes pain. The primary purpose of this study is firstly to identify the prevalence rate of OAB symptoms in patients with BPS/IC, secondly to identify changes in OAB symptoms after low-dose triple therapy, and thirdly to build a theoretical foundation to improve quality of life for patients. METHODS Patients who met the inclusion criteria of BPS/IC through basic tests including the O'Leary-Sant symptom index, overactive bladder symptom score (OABSS), and visual analog scale (VAS) were identified. Treatment-based changes in OAB symptoms were identified using the IC Symptom Index and IC Problem Index (ICSI/ICPI), OABSS, and VAS before, and 4 and 12 weeks after low-dose triple therapy. RESULTS The patients consisted of 3 men and 20 women, and their mean age was 61.9 years (41.0-83.2 years). Comparing values before treatment, and 4 and 12 weeks after treatment (baseline vs. 4 weeks to baseline vs. 12 weeks), the rates of improvement were as follows: ICSI, 44.2% to 63.7%; ICPI, 46.9% to 59.4%; OABSS, 34.3% to 58.2%; and VAS, 53.6% to 75.0%, which showed statistically significant differences (P<0.05). However, comparing values at 4 and 12 weeks after treatment (4 weeks vs. 12 weeks), the ICSI and VAS showed a statistically significant decrease (P<0.05). The ICPI and OABSS showed slight improvement, but no statistically significant differences (P>0.05). CONCLUSIONS Low-dose triple therapy in BPS/IC results in a clear decrease in OAB symptoms in the first 4 weeks after treatment, and additional treatment for 8 weeks had a partial effect with varied statistical significances depending on the questionnaires.