Pharmacotherapy for bladder spasm and irritative lower urinary tract symptoms associated with intravesical therapy for bladder cancer: a review of available evidence.

Bladder spasms and irritative lower urinary tract symptoms (LUTS) are a common complication following urologic procedures, causing significant discomfort and potentially compromising therapeutic outcomes. Intravesical therapy, which enables localized drug delivery and limits systemic toxicity, relies on the urinary bladder as a reservoir accessible via urethral catheterization. However, direct mucosal exposure to chemotherapeutic and immunotherapeutic agents frequently provokes irritative LUTS, ranging from dysuria and discomfort to bladder spasms. In patients receiving intravesical therapy for non-muscle-invasive bladder cancer (NMIBC), spasms may lead to premature drug expulsion, severe cystitis symptoms or discontinuation of therapy. This concern is of particular relevance given the recent approval of several novel intravesical agents for the treatment of Bacillus Calmette-Guérin (BCG)-unresponsive NMIBC, including nadofaragene firadenovec and nogapendekin alfa inbakicept. While evidence for managing adverse urinary symptoms with these newer agents remains limited, various management strategies, such as anticholinergics, β3-adrenergic agonists, and adjunctive therapies, have been explored for similar presentations. In this review, we evaluate the etiology of bladder spasms and irritative LUTS associated with currently approved intravesical therapies for bladder cancer and current approaches to preventing and managing them. By synthesizing available evidence and clinical practice insights, we aim to provide practical recommendations to optimize intravesical therapy for bladder cancer outcomes.