General:
If malignant hyperthermia develops, discontinue administration immediately and institute therapeutic countermeasures as clinically indicated.
Lidocaine hydrochloride should not be added to blood transfusion assemblies because of the possibilities of pseudoagglutination or hemolysis.
Laboratory Tests:
Clinical evaluation and periodic laboratory determinations are necessary to monitor changes in fluid balance, electrolyte concentrations, and acid-base balance during prolonged parenteral therapy or whenever the condition of the patient warrants such evaluation.
Drug Interactions:
Pharmacodynamics Interactions
Digitalis derivatives: Monitor toxicity when lidocaine is used in patients with digitalis toxicity accompanied by supraventricular arrhythmia and/or atrioventricular block (see
CONTRAINDICATIONS).
When lidocaine is administered with other antiarrhythmic drugs such as amiodarone, phenytoin, procainamide, propranolol or quinidine, the cardiac effects may be additive or antagonistic and toxic effects may be additive.
Pharmacokinetics Interactions
Concomitant treatment with drugs which are inhibitors of CYP1A2 and/or CYP3A4 has the potential to increase lidocaine plasma levels by decreasing lidocaine clearance and thereby prolonging the elimination half-life. Monitor toxicity when administering lidocaine with CYP1A2 and/or CYP3A4 inhibitors.
Concomitant use of lidocaineat steady-state concentrations of the CYP1A2 inhibitor fluvoxamine increases intravenous lidocaine plasma AUC and Cmax by 71% and 22%, and decreases MEGX AUC and Cmax by 54% and 65%. Fluvoxamine decreases the plasma clearance of lidocaine by 41%-60% and prolonged the mean half-life by one hour. Monitor toxicity when coadministering these medications.
Concomitant use of lidocaine with propofol, a hypnotic agent and CYP3A4 inhibitor, may increase lidocaine plasma levels by reducing lidocaine clearance. Monitor toxicity when coadministering lidocaine with propofol.
Concomitant treatment with drugs which are inducers of CYP1A2 and/or CYP3A4 (e.g., phenytoin) has the potential to decrease lidocaine plasma levels and higher doses may be required.
Concomitant use of lidocaine with a weak CYP1A2 and CYP3A4 inhibitor has been reported to increase lidocaine plasma levels by 24% – 75% and may result in toxic accumulation of the drug. Monitor toxicity when coadministering lidocaine with cimetidine.
Beta-adrenergic blockers (e.g. propranolol): Concomitant use of lidocaine with beta-adrenergic blockers may increase lidocaine plasma levels by decreasing hepatic blood flow and thereby decrease lidocaine clearance. Monitor for toxicity when coadministering lidocaine with drugs that decrease hepatic blood flow.
Carcinogenesis, Mutagenesis, and Impairment of Fertility:
Long term animal studies have not been performed to evaluate carcinogenic potential, mutagenic potential or the effect on fertility of lidocaine hydrochloride.
Pregnancy:
Teratogenic Effects:
Reproduction studies have been performed in rats at doses up to five times the maximum human dose 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, physicians should carefully consider the potential risks and benefits for each specific patient before prescribing lidocaine hydrochloride.
Lidocaine may cross the placental barrier.
Nursing Mothers:
Lidocaine is present in human milk. Published studies have reported a range of lidocaine milk: plasma ratios between 0.4-1.1. Limited data available on lidocaine’s effects on the breastfed child have not revealed a consistent pattern of associated adverse events. The development and health benefits of breastfeeding should be considered along with the mother’s clinical need for lidocaine and any potential adverse effects on the breastfed infant from lidocaine or from the underlying maternal condition.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.
Geriatric Use
Clinical studies of Lidocaine Hydrochloride did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.