[Skip to Navigation]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
May 1985

Lidocaine Plasma Concentrations Following Administration of Intraoral Lidocaine Solution

Author Affiliations

From the Division of Clinical Pharmacology, Tufts-New England Medical Center, Boston (Dr Greenblatt and Messrs Willis and Harmatz); the Medical Department, Astra Pharmaceuticals, Worcester, Mass (Dr Benjamin); and Medical and Technical Research Associates, Inc, Needham, Mass, and Boston (Dr Zinny).

Arch Otolaryngol. 1985;111(5):298-300. doi:10.1001/archotol.1985.00800070050005

• Seventeen healthy male volunteers received 15 mL of 2% solution (300 mg) of lidocaine hydrochloride every three hours for eight consecutive doses. Modes of administration were as follows: (A) each dose washed throughout the oral cavity, then spit out without swallowing; (B) each dose washed, then swallowed; and (C) each dose swallowed directly. Plasma levels of lidocaine and its two metabolites (monoethylglycinexylidide [MEGX] and glycinexylidide [GX]) were measured during and after the period of dosage. In trial A, levels of all three compounds were very low, in no case exceeding 0.3 μg/mL. During trial C, the mean peak levels of lidocaine and MEGX, respectively, were 0.5 and 0.6 μg/mL after the first dose, and 0.8 and 1.3 μg/mL after the eighth dose. Both compounds were essentially undetectable by 12 hours after the last dose. Levels in trial B were very similar to those in trial C. Thus, recommended topical oral cavity use of 2% lidocaine leads to negligible systemic levels of lidocaine and metabolites. Even when doses are swallowed, systemic levels do not approach a toxic range.

(Arch Otolaryngol 1985;111:298-300)