Purpose: The viability of bacillus Calmette-Guerin (BCG) is crucial for induction of a local immune response and for effective therapy of recurrent superficial bladder carcinoma. During intravesical instillation of BCG lubricants are administered to assist catheterization, which contain bacteriostatic components that may interfere with the viability of mycobacteria. To verify this assumption, 5 commercially available lubricants were analyzed with regard to inhibition of viable BCG growth.
Materials and methods: Five different lubricants and their components were co-incubated with Connaught strain BCG and the resultant growth of BCG was assessed. To prove the significant passage of lubricants into the bladder, fluid was recovered from the bladder after catheterization, analyzed with regard to the bacteriostatic effect and compared to normal urine of different acidity.
Results: Significant impairment of BCG viability, dependent on dosage and time of co-incubation, was noted with all lubricants analyzed. Several components, namely lidocaine hydrochloride, glyceryl stearate, propyl-4-hydroxy-benzoate and chlorhexidine digluconate, were identified as responsible for this inhibition. Fluid recovered from the bladder after lubricant assisted catheterization also showed an inhibitory effect, indicating significant mixture of the instillate with lubricants.
Conclusions: Generous use of lubricants to assist catheterization during intravesical BCG therapy will result in a clinically significant decrease in the number of intravesically instilled viable mycobacteria. For this reason, during intravesical immunotherapy with BCG only small amounts of lubricants should be used for urethral catheterization, and use of catheters not requiring lubricants should be considered.