Lack of local anesthetic properties of lidocaine gel in an experimental model

Introduction: Many reports negate the anesthetic properties of lidocaine gel placed in the urethra during catheterization. The anesthetic action of lidocaine is inseparably associated with the toxic action of this compound on cells.

Materials and methods: A primary rabbit urothelial cell culture (PRUCC) was previously established as a monolayer. The effect of 2% lidocaine gel on the viability of the PRUCC was assessed and compared with the cytotoxic effect of decreasing concentrations of lidocaine solution. Cell viability was evaluated after 1-hour exposure using the trypan blue exclusion test.

Results: The 2% lidocaine gel did not show cytotoxic properties after 1 h of incubation on a PRUCC. The 2 and 1% lidocaine solutions induced statistically significant decreases in the viability of the PRUCC after 1 h of incubation.

Conclusions: Experimental tests evaluating the cytotoxicity of local anesthetics may prove to be an objective measure of the accessibility of these substances to cells and their anesthetic action.