The efficacy profile of lidocaine as a local anesthetic is characterized by a rapid onset of action and intermediate duration of efficacy. Therefore, lidocaine is suitable for infiltration, block, and surface anesthesia. Longer-acting substances such as bupivacaine are sometimes given preference for subdural and epidural anesthesias; lidocaine, though, has the advantage of a rapid onset of action. Epinephrine (adrenaline) vasoconstricts arteries, reducing bleeding and also delays the resorption of lidocaine, almost doubling the duration of anaesthesia. For surface anesthesia, several available formulations can be used for endoscopies, before intubations, etc. Buffering the pH of lidocaine makes local freezing less painful.Lidocaine drops can be used on the eyes for short ophthalmic procedures.
There is tentative evidence for topical lidocaine for neuropathic pain.Intravenous lidocaine also has uses as a temporary fix for tinnitus. Although not completely curing the disorder, it has been shown to reduce the effects by around two-thirds.
Lidocaine crosses the blood-brain and placental barriers, presumably by passive diffusion.
Lidocaine is metabolized rapidly by the liver, and metabolites and unchanged drug are excreted by the kidneys. Biotransformation includes oxidative N-dealkylation, ring hydroxylation, cleavage of the amide linkage, and conjugation. N-dealkylation, a major pathway of biotransformation, yields the metabolites monoethylglycinexylidide and glycinexylidide. The pharmacological/toxicological actions of these metabolites are similar to, but less potent than, those of Lidocaine. Approximately 90% of Lidocaine administered is excreted in the form of various metabolites, and less than 10% is excreted unchanged.
Local Anesthetic Lidocaine
Lidocaine Basic Information:
Product Name: Lidocaine
Lidocaine CAS: 137-58-6
Lidocaine MF: C14H22N2O
Lidocaine MW: 234.34
Lidocaine EINECS: 205-302-8
Lidocaine mp: 66-69°C
Lidocaine storage temp: Store at RT
Lidocaine solubility ethanol: 4 mg/mL
Lidocaine form: powder
Lidocaine Water Solubility: practically insoluble
Lidocaine Stability: Stable. Incompatible with strong oxidizing agents.
Lidocaine Usage: Lidocaine is a selective inverse peripheral histamine H1-receptor agonist with an IC50 of >32 μM.