Potential diversion of local anesthetics from dental offices for use as cocaine adulterants

Abstract

Background: Reports of lidocaine and benzocaine in the bloodstreams of people who abuse cocaine with accompanying reports of seizures and methemoglobinemia indicate that there is a potential that local anesthetics are being diverted from dental offices and being used as cocaine adulterants. These adulterants augment the nasal numbness produced by inhaling cocaine.

Methods: The authors conducted a PubMed search by using the following terms: "adulterants," "benzocaine," "cocaine," "lidocaine" and "methemoglobinemia."

Results: The authors identified two case reports as a result of their PubMed search. Each case involved a patient with symptoms of both cocaine overdose and methemoglobinemia who sought treatment at an emergency department. The results of urine samples from each patient, as well as the results from an analysis of a sample of one patient's cocaine, revealed the presence of many adulterants, including lidocaine and benzocaine.

Conclusions: Injectable lidocaine and topical benzocaine are cheap and readily available substances found in dental offices that may be diverted by anyone-including dentists, office staff members or patients-to adulterate cocaine.

Practical implications: Additional research is needed to identify whether dental offices are a common source of cocaine adulterants. The authors recommend that dentists keep track of their local anesthetic supplies.

Keywords: Lidocaine; dental anesthetics; drug abuse; drug contamination; drug interactions; drugs; local anesthetics; pharmacology; topical anesthetics.