Lidocaine Hydrochloride

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LIE-doe-kane High-dro-KLOR-ide - Pronunciation guide

Brand Names

  • Lidocaine HCI 2%
  • Lidocaine HCI Injectable 2%
  • Lidocaine Hydrochloride Injectable 2%
  • LidoJect


Rx symbolLidocaine HCI occurs as a white, odorless, slightly bitter-tasting, crystalline powder. It is soluble in water and alcohol. It is also known as lignocaine HCI.


Lidocaine HCI is a potent local anesthetic and anti-arrhythmic agent. It is compatible with most commonly used IV infusion solutions. Compatibility is dependent upon factors, such as pH, concentration, temperature, and dilutents used. It is considered to be a class IB (membrane-stabilizing) anti-dysrhythmic agent.

Besides its use as a local and topical anesthetic, lidocaine is used to treat ventricular arrhythmias.

Dosage and Administration

Prescription medicationLidocaine Hydrochloride
Method Dosage Concentration Period Duration
Injection1 5-15 ml 2% solution Treatment NA
Injection2 5-20 ml 2% solution Treatment NA
Injection3 4 ml 0.5% solution Treatment NA


  • Federal law restricts this drug to use by or on the order of a licensed veterinarian.
  • Extra-label use of drugs in treating animals is allowable only by licensed veterinarians within the context of a valid veterinarian-client-patient relationship, and does not include drug use in treating animals by the layman (except under the supervision of a licensed veterinarian).
  • 1Epidural.
  • 2Nerve block.
  • 3Infiltration. Mix 1 mL of 2% solution diluted with 3 mL of sterile water = 4 mL of a 0.5% solution

Side Effects

Toxic effects are usually related to central nervous system effects. Excitability, muscle tremors, and convulsions have been noted. Weakness and recumbency occur, but quickly disappear after discontinuation of the infusion.


Caution should be used in horses with liver disease, congestive heart failure, shock, and respiratory depression.

Be sure not to use a product that contains epinephrine intravenously.

Lidocaine Hydrochloride is FDA-approved for use in horses. It is a prescription drug restricted to use by or on the lawful written or oral order of a licensed veterinarian.

The appropriate individual regulatory body should be consulted regarding use of Lidocaine HCI in competition horses.


Licocaine effects may be increased by concomitant administration of cimetidine or propranolol. Other anti-arrhythmics administered with lidocaine may cause additive or antagonistic cardiac effects and toxicity may be enhanced. When given IV with phenytoin, increased cardiac depression may occur. Lidocaine may cause increased creatine kinase levels.


Overdose symptoms include ataxia, depression, seizures, hypotension, and, at very high levels, circulatory collapse. Because lidocaine is rapidly metabolized, cessation of therapy or reduction of infusion rate may be all that is required to relieve minor symptoms. Seizures or excitement may be treated with diazepam or a short-acting barbiturate. Longer-acting barbiturates, such as pentobarbital should be avoided. If circulatory depression occurs, treat with fluids, pressor agents and, if necessary, begin CPR.


Lidocaine Hydrochloride Injectable-2%Lidocaine Hydrochloride Injectable-2%

Lidocaine Hydrochloride Injectable-2%Lidocaine Hydrochloride Injectable-2%



About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.