title: Stability of buffered lidocaine and epinephrine used for local anesthesia.
abstract: Buffered lidocaine has been recently recommended for local anesthesia, as there is less pain on injection of the buffered solution. Reduced pain on injection of lidocaine and epinephrine buffered to a neutral pH was confirmed in 20 subjects (P less than .01). Concentrations of buffered lidocaine and epinephrine were performed in order to evaluate their stability. Buffered lidocaine dropped to 66.1% of initial concentrations after 4 weeks when stored at 25 degrees C. Buffered epinephrine fell to 1.34% of its initial concentration under similar conditions. Buffered lidocaine and epinephrine maintained 94.54% and 82.04%, respectively, of their initial concentrations after 4 weeks when refrigerated at 0-4 degrees C. Both lidocaine and epinephrine maintained greater than 90% concentration 2 weeks after buffering when stored at 0-4 degrees C. This permits batch buffering of lidocaine with epinephrine and storage for periods up to 2 weeks when properly refrigerated.
authors.affiliation: Department of Surgery, University of Wisconsin Hospital/Clinic, Madison.
authors.forename: P O
authors.initials: PO
authors.lastname: Larson
authors.forename: G
authors.initials: G
authors.lastname: Ragi
authors.forename: M
authors.initials: M
authors.lastname: Swandby
authors.forename: B
authors.initials: B
authors.lastname: Darcey
authors.forename: G
authors.initials: G
authors.lastname: Polzin
authors.forename: P
authors.initials: P
authors.lastname: Carey
mesh_terms: D000772:Anesthesia, Local; D002021:Buffers; D004338:Drug Combinations; D004355:Drug Stability; D004356:Drug Storage; D004837:Epinephrine / Q000009:adverse effects / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008012:Lidocaine / Q000009:adverse effects / Q000737:chemistry*; D010146:Pain / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D010147:Pain Measurement; D013696:Temperature
chemical_list: D002021:Buffers; D004338:Drug Combinations; D008012:Lidocaine; D004837:Epinephrine