Comparison of the Effect of Oral Sodium Bicarbonate and Tolterodine in Women with Symptoms of Overactive Bladder with Acidic Urine- A Single-Blind Randomized Clinical Trial

Background: Urine alkalinization with oral sodium bicarbonate seems to improve urinary symptoms in female patients with overactive bladder with acidic urinary pH. Aim: Therefore, the aim of this study was to compare the effect of oral sodium bicarbonate and tolterodine in women with symptoms of overactive bladder with acidic urinary pH. Methods: In this single-blind randomized clinical trial, 72 female patients with symptoms of overactive bladder syndrome with acidic urinary pH in the age group of 28-60 years were referred to the gynecology clinic of Mahdieh Hospital affiliated with Shahid Beheshti University of Medical Sciences, Tehran, Iran in 2021-2022 were studied. These patients were randomly divided into two groups oral sodium bicarbonate (36 patients) and tolterodine group (36 patients) and received the treatment for one month. Group matching was performed between patients. At the end of the study, the Overactive Bladder- Validated 8-question Awareness tool (OAB-V8), frequency, nocturia, urgency, and urinary incontinence (UI) was measured and compared between patients in the two groups. Results: Patients were matched for age, underlying disease, BMI, acidic urinary pH, and menopause status at the baseline. After 30 days of medication therapy, a significant decrease in OAB-V8 score, frequency, nocturia, urgency, and urinary incontinence (UI) was observed in both groups receiving oral sodium bicarbonate and tolterodine in female patients with symptoms of overactive bladder syndrome with acidic urine. The degree of improvement in outcomes after treatment was similar between both groups. Conclusion: Oral sodium bicarbonate administration in patients with overactive bladder with acidic urinary pH has a significant positive effect on OAB-V8 symptoms, frequency, nocturia, urgency, and urinary incontinence (UI) and these results are similar to tolterodine treatment. Given that the acidic urinary pH may play a role in the etiology of an overactive bladder, it seems that sodium bicarbonate improves the symptoms of an overactive bladder by alkalizing the urine.