Drug Groups

approved

Description

A local anesthetic and cardiac depressant used as an antiarrhythmia agent. Its actions are more intense and its effects more prolonged than those of procaine but its duration of action is shorter than that of bupivacaine or prilocaine. [PubChem]

Indication

For production of local or regional anesthesia by infiltration techniques such as percutaneous injection and intravenous regional anesthesia by peripheral nerve block techniques such as brachial plexus and intercostal and by central neural techniques such as lumbar and caudal epidural blocks.

Pharmacology

Lidocaine is an anesthetic agent indicated for production of local or regional anesthesia and in the treatment of ventricular tachycardia occurring during cardiac manipulation, such as surgery or catheterization, or which may occur during acute myocardial infarction, digitalis toxicity, or other cardiac diseases. The mode of action of the antiarrhythmic effect of Lidocaine appears to be similar to that of procaine, procainamide and quinidine. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. The sinoatrial node is, however, unaffected. In contrast to the latter 3 drugs, Lidocaine in therapeutic doses does not produce a significant decrease in arterial pressure or in cardiac contractile force. In larger doses, lidocaine may produce circulatory depression, but the magnitude of the change is less than that found with comparable doses of procainamide.

Toxicity

The oral LD 50 of lidocaine HCl in non-fasted female rats is 459 (346-773) mg/kg (as the salt) and 214 (159-324) mg/kg (as the salt) in fasted female rats. Symptoms of overdose include convulsions, hypoxia, acidosis, bradycardia, arrhythmias and cardiac arrest.

Affected Organisms

Biotransformation

Primarily hepatic.

Absorption

Information derived from diverse formulations, concentrations and usages reveals that lidocaine is completely absorbed following parenteral administration, its rate of absorption depending, for example, upon various factors such as the site of administration and the presence or absence of a vasoconstrictor agent.

Half Life

109 minutes

Protein Binding

60-80%

Elimination

Lidocaine and its metabolites are excreted by the kidneys.

Distribution

* 0.7 to 2.7 L/kg [healthy volunteers]

Clearance

* 0.64 +/- 0.18 L/min

References

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