Adverse drug reactions of intravesical bacillus Calmette-Guérin instillation and risk factors of the development of adverse drug reactions in superficial cancer and carcinoma in situ of the bladder

Background: We examined the incidence and severity of adverse drug reactions following intravesical bacillus Calmette–Guérin (BCG) instillation for superficial bladder cancer including carcinoma in situ. We investigated the relationship between adverse drug reactions and patient background to clarify risk factors for the development of adverse drug reactions. Methods: A total of 123 patients who underwent intravesical BCG instillation for treatment and prophylaxis between April 1997 and June 2000 were included in this study. Adverse drug reactions were divided into local and systemic categories and the severity of reactions was classified according to the presence or absence of postponement or discontinuation of instillation, with or without treatment for the reaction itself. Results: Of 123 patients, 95.9% showed adverse drug effects and 50.4% needed some sort of treatment. Discontinuation of instillation due to adverse drug reactions was observed in nine patients. Regarding the necessity of treatment for adverse drug effects, the purpose of instillation and BCG dose were independent significant factors on multivariate analysis. Conclusion: Although there was a high rate of adverse drug reactions after intravesical BCG instillation, the rate of discontinuation of instillation was not high and serious adverse reactions were rare. The scale of the present study was small, but these results suggest that BCG instillation was well tolerated. When instillation is being performed for the purpose of treatment, and the BCG dose is 80 mg, greater attention might be needed to monitor for the development of adverse drug effects.