Pharmacokinetics and metabolism of lidocaine HCl 2

Lidocaine is a local anesthetic that is sometimes administered in combination with epinephrine. The addition of epinephrine increases the time lidocaine remains at the site of administration, thus prolonging the duration of effect. Due to their potential to prevent the visual detection of lameness, the administration of local anesthetics is strictly regulated in performance and racehorses. Recent reports of positive regulatory findings for lidocaine in racehorses suggests a better understanding of the behavior of this drug is warranted. The objective of the current study was to describe serum and urine concentrations and the pharmacokinetics of lidocaine and its primary metabolites following administration in combination with epinephrine, as a palmar digital nerve block in horses. Twelve horses received a single administration of 1 mL of 2