Effects of Lidocaine and Articaine on Neuronal Survival and Recovery

The local anesthetics lidocaine and articaine are among the most widely used drugs in the dentist's arsenal, relieving pain by blocking voltage-dependent Na+ channels and thus preventing transmission of the pain signal. Given reports of infrequent but prolonged paresthesias with 4% articaine, we compared its neurotoxicity and functional impairment by screening cultured neural SH-SY5Y cells with formulations used in patients (2% lidocaine + 1:100,000 epinephrine or 4% articaine + 1:100,000 epinephrine) and with pure formulations of the drugs. Voltage-dependent sodium channels Na(v)1.2 and Na(v)1.7 were expressed in SH-SY5Y cells. To test the effects on viability, cells were exposed to drugs for 5 minutes, and after washing, cells were treated with the ratiometric Live/Dead assay. Articaine had no effect on the survival of SH-SY5Y cells, while lidocaine produced a significant reduction only when used as pure powder. To determine reversibility of blockage, wells were exposed to drugs for 5 minutes and return...