June 9, 2023

Lidocaine, like the other local anesthetics (LA) discussed in this report, is a synthetic compound useful in medical procedures as an anesthetic, usually available as an over-the-counter (OTC) topical cream, transdermal patch, or injectable solution administered in a medical procedure. The numbing sensation is caused by the blockade of neuronal sodium channels, thus reducing the transmission of pain signals. Because local anesthetics produce a numbing sensation, they may be added in minor amounts to reduce the discomfort involved with injecting or snorting drugs. While lidocaine is the LA most frequently combined with illicit drugs, other LA compounds that could be added to drug samples include benzocaine, procaine, tetracaine, mepivacaine, and bupivacaine.