Pharmacokinetics
Lidocaine is approximately 95% metabolized (dealkylated) in the liver by CYP3A4 to the pharmacologically-active metabolites monoethylglycinexylidide (MEGX) and then subsequently to the inactive glycine xylidide. MEGX has a longer half life than lidocaine but also is a less potent sodium channel blocker.
The elimination half-life of lidocaine is approximately 90–120 minutes in most patients. This may be prolonged in patients with hepatic impairment (average 343 minutes) or congestive heart failure (average 136 minutes).
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