1\. General: Caution should be employed in the use of lidocaine hydrochloride in patients with severe liver or kidney disease because accumulation of the drug or metabolites may occur.  
Lidocaine Hydrochloride Injection, USP should be used with caution in the treatment of patients with hypovolemia, severe congestive heart failure, shock and all forms of heart block. 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 rate (e.g., by atropine, isoproterenol or electric pacing) may promote more frequent and serious ventricular arrhythmias or complete heart block. (See CONTRAINDICATIONS).

Dosage should be reduced for pediatric patients and for debilitated and/or elderly patients, commensurate with their age and physical status.

The safety of amide local anesthetic agents in patients with genetic predisposition of malignant hyperthermia has not been fully assessed; therefore, lidocaine should be used with caution in such patients.

In hospital environments where drugs known to be triggering agents for malignant hyperthermia (fulminant hypermetabolism) are administered, it is suggested that a standard protocol for management should be available.

It is not known whether lidocaine may trigger this reaction; however, large doses resulting in significant plasma concentrations, as may be achievedby intravenous infusion, pose potential risk to these individuals. Recognition of early unexplained signs of tachycardia, tachypnea, labile blood pressure and metabolic acidosis may precede temperature elevation. Successful outcome is dependent on early diagnosis, prompt discontinuance of the triggering agent and institution of treatment including oxygen therapy, supportive measures and dantrolene (for details see dantrolene package insert).

2\. Patient Information:  
The patient should be advised of the possible occurrence of the experiences listed under ADVERSEREACTIONS.

3. Laboratory Tests:   
None known.

4\. Drug Interactions: Lidocaine Hydrochloride Injection, USP should be used with caution in patients with digitalis toxicity accompanied by atrioventricular block. Concomitant use of beta-blocking agents or cimetidine may reduce hepatic blood flow and thereby reduce lidocaine clearance. The concomitant use of these two agents may cause an increased incidence of adverse reactions, including central nervous system adverse reactions such as seizure. Lidocaine and tocainide are pharmacodynamically similar.

5\. Carcinogenesis, Mutagenesis, Impairment of Fertility: Long term studies in animals to evaluate the carcinogenic and mutagenic potential or the effect on fertility of lidocaine HCl have not been conducted.

6. Pregnancy: TeratogenicEffects: Reproduction studies have been performed in rats at doses up to 6.6 times the maximum human doses and have revealed no significant findings. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

7\. Labor and Delivery: The effects of lidocaine HCl on the mother and the fetus, when used in the management of cardiac arrhythmias during labor and delivery are not known. Lidocaine readily crosses the placental barrier.  
  
8\. Nursing Mothers: It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when lidocaine is administered to a nursing woman.

9\. Pediatric Use: Controlled clinical studies have not been conducted in the pediatric population to establish safety and efficacy in this population (see DOSAGE AND ADMINISTRATION).