Background <p>Urodynamic findings in overactive bladder (OAB) patients vary, with some exhibiting detrusor overactivity (DO) while others show stable bladder. However, the relationship between urodynamic findings and therapeutic responses to antimuscarinic agents remains poorly understood.</p> Objective <p>This study aims to evaluate whether urodynamic findings, specifically the presence of detrusor overactivity (DO), predict the efficacy of trospium chloride in treating OAB symptoms in female patients.</p> Methods <p>A prospective, randomized, double-blind, placebo-controlled study was conducted involving 55 women with OAB symptoms for at least 6 months. Urodynamic testing was performed to classify patients into two groups: DO (with detrusor overactivity) and WDO (without detrusor overactivity). Patients were treated with either trospium chloride (20&#xa0;mg twice daily) or placebo for 6&#xa0;weeks. Primary outcomes included changes in symptoms, voiding parameters, and quality of life.</p> Results <p>Of the 55 patients with idiopathic OAB, 27 (49%) had DO, and 28 (51%) had WDO. Baseline characteristics differed significantly between groups. After treatment, both groups showed improvements in the mean voided volume, frequency of micturitions, nocturia episodes, and urgency/incontinence episodes, with no significant differences between the DO and WDO groups. Both groups also showed a similar response to placebo.</p> Conclusion <p>The therapeutic efficacy of trospium chloride in female patients with idiopathic OAB was not significantly influenced by the presence of detrusor overactivity, suggesting that urodynamic testing may not be necessary for predicting treatment outcomes in OAB patients. This finding supports current guidelines that recommend empirical treatment for OAB without requiring urodynamic confirmation of detrusor overactivity.</p> Trial Registration <p>ISRCTN17587199, Registration date 11/02/2025.</p>