Lidocaine hydrochloride administered intravenously is specifically indicated in the acute management of (1) ventricular arrhythmias occurring during cardiac manipulations, such as cardiac surgery and (2) life-threatening arrhythmias which are ventricular in origin, such as occur during acute myocardial infarction.

Constant monitoring with an electrocardiograph is essential to the administration of lidocaine hydrochloride intravenously.

Signs of excessive depression of cardiac conductivity, such as prolongation of the PR interval, widening of the QRS interval and the appearance or aggravation of arrhythmias, should be followed by prompt cessation of the intravenous infusion of this agent.

It is mandatory to have emergency resuscitative equipment and drugs immediately available to manage adverse reactions involving cardiovascular, respiratory, or central nervous systems.

Central nervous system adverse reactions are associated with venous plasma levels above 6.0 μg free base per mL (see ADVERSE REACTIONS).

Hypersensitivity, including anaphylaxis, has been reported with lidocaine-containing solutions.

Stop the infusion immediately if signs of hypersensitivity develop.

Acceleration of ventricular rate may occur in patients with atrial fibrillation or flutter treated with lidocaine.

In patients with sinus bradycardia or incomplete heart block, the administration of lidocaine hydrochloride intravenously for the elimination of ventricular ectopic beats without prior acceleration in heart r ate (e.g., by isoproterenol or by electric pacing) may promote more frequent and serious ventricular arrhythmias or complete heart block (see Contraindications).

Because lidocaine is metabolized mainly in the liver and excreted by the kidneys, patients with renal or hepatic insufficiency may be at increased risk for toxicity.

Systemic reactions of the following types have been reported: Nervous System Disorders: respiratory depression and arrest; unconsciousness; convulsions; tremors; twitching; vomiting; blurred or double vision; drowsiness; dizziness; light-headedness; tinnitus; sensation of heat, cold or numbness; euphoria; apprehension; agitation; confused state; paresthesia; dysarthria.

Cardiovascular System: cardiovascular arrest; bradycardia which may lead to cardiac arrest; hypotension, Ventricular fibrillation, Ventricular tachycardia, Ventricular arrhythmia, Asystole.

Gastrointestinal Disorders: Hypoesthesia oral, Nausea, Hematologic Effects: methemoglobinemia.

Psychiatric Disorders: Disorientation Allergic reactions, including anaphylactic reactions, may occur but are infrequent.

There have been no reports of cross sensitivity between lidocaine hydrochloride and procainamide or between lidocaine hydrochloride and quinidine.