Lidocaine Hydrochloride

Introduction Overview

Generic Name

lidocaine hydrochloride

Brand Name

Xylocaine Jelly

Dosage Form

jelly (topical aqueous gel)

Drug Class

Topical anesthetics

Pharmacokinetics

Absorption: Lidocaine is absorbed through mucous membranes following topical application; the rate and extent of absorption depend on factors such as the concentration applied, total dose, site of application, and duration of exposure. The absorption is rapid after intratracheal administration and more variable from urethral or other mucosal surfaces. When applied topically to intact skin, lidocaine absorption is negligible and thus ineffective. Clinically, systemic absorption following urethral or endotracheal mucosal application can lead to measurable plasma lidocaine concentrations, necessitating dose vigilance, especially in susceptible populations.

Distribution: Lidocaine is widely distributed throughout the body after absorption, readily crossing the blood-brain barrier and placental barrier via passive diffusion. Its plasma protein binding is concentration-dependent, with 60-80% bound to alpha-1-acid glycoprotein at therapeutic plasma concentrations (1-4 mcg/mL). The volume of distribution is influenced by tissue perfusion and binding, with significant penetration into highly perfused organs such as the brain, heart, and lungs. This extensive distribution underlies both its efficacy and potential toxicity.

Metabolism: Lidocaine undergoes extensive hepatic metabolism primarily via oxidative N-dealkylation producing active metabolites monoethylglycinexylidide and glycinexylidide. Other metabolic pathways include ring hydroxylation, amide linkage cleavage, and conjugation. These metabolites possess similar but less potent pharmacological and toxicological effects compared to the parent compound. Approximately 90% of administered lidocaine is metabolized hepatically, a process subject to alteration in patients with liver impairment, which significantly prolongs elimination half-life.

Elimination: Lidocaine and its metabolites are excreted mainly via the kidneys, with less than 10% of the drug excreted unchanged. The elimination half-life is typically 1.5 to 2 hours in healthy individuals but may double or more in hepatic dysfunction. Renal impairment does not markedly alter lidocaine kinetics but may cause accumulation of metabolites. Clearance is influenced by hepatic blood flow and enzyme activity. Clinical monitoring in patients with compromised hepatic or renal function is warranted to avoid toxicity.

Dosage Forms

Available Dosage Forms: Xylocaine Jelly is supplied as a sterile 2% lidocaine hydrochloride aqueous jelly formulation contained in aluminum tubes. Available sizes include 5 mL and 30 mL tubes. The jelly contains additional components such as hypromellose to ensure mucosal adhesion and lubrication, along with methylparaben and propylparaben as preservatives.

Dosages for Adults and Adolescents: For male urethral anesthesia, approximately 15 mL (300 mg lidocaine HCl) is slowly instilled into the urethra using a sterilized plastic cone, followed by application of a penile clamp for several minutes. A second dose of up to 15 mL can be administered for adequate anesthesia, with a maximum total dose of 30 mL (600 mg lidocaine HCl). For female urethral procedures, 3 to 5 mL (60 to 100 mg lidocaine HCl) is introduced slowly into the urethra; anesthesia develops over several minutes.

For endotracheal intubation, a moderate amount of jelly is applied externally on the tube before use, avoiding entry into the lumen to prevent lumen occlusion due to dried residue.

Specific Patient Populations: Dosing should be reduced in pediatric, elderly, debilitated, or acutely ill patients due to altered pharmacodynamics and increased sensitivity. For pediatric patients under ten years, dosing is calculated based on weight (maximum 4.5 mg/kg) with careful monitoring. For hepatic impairment, the half-life is prolonged, necessitating dosage adjustments or increased intervals between applications. Caution is warranted in patients with sepsis or severe mucosal trauma due to potential increased rates of systemic absorption. The maximum total dose should not exceed 600 mg lidocaine HCl in any 12-hour period to minimize systemic toxicity.

Mechanism Of Action

Lidocaine, the active ingredient in Xylocaine Jelly, is a potent local anesthetic agent that exerts its effect by stabilizing neuronal membranes. It achieves this through the reversible inhibition of voltage-gated sodium channels located in the neuronal cell membrane. By blocking these channels, lidocaine prevents the influx of sodium ions during depolarization, thereby halting the initiation and propagation of action potentials along sensory nerves responsible for transmitting pain signals.

At the cellular level, lidocaine’s blockade of sodium channels impedes the rapid depolarization phase of nerve impulses. This disrupts nerve conduction in nociceptive fibers, effectively producing localized anesthesia without affecting motor function significantly when used judiciously. The result is loss of sensation and numbness in the area of application, facilitating pain-free instrumentation or minor surgical procedures.

Biochemically, lidocaine binds preferentially to the intracellular portion of the sodium channel in its activated state and has a higher affinity for rapidly firing nerves, which confers use-dependent block. This property enhances its efficacy in anesthetizing hyperactive or inflamed tissue. Lidocaine also exhibits some membrane-stabilizing effects on cardiac myocytes, which is relevant to its antiarrhythmic uses but is less pronounced at topical doses.

Clinically, Xylocaine Jelly’s combination of lidocaine and hypromellose not only ensures effective anesthesia by maximizing mucosal contact and absorption but also provides lubrication during procedures such as urethral catheterization and endotracheal intubation. Compared to other topical anesthetics, lidocaine’s rapid onset (3 to 5 minutes) and moderate duration render it suitable for short-duration urological and airway procedural anesthesia. Numerous clinical studies have confirmed its safety and efficacy when used within recommended doses, underscoring its role as a first-line agent for topical anesthesia in mucosal applications.

Pharmacological Actions

Local anesthetic effect via reversible blockade of voltage-gated sodium channels in neuronal membranes.
Inhibition of nerve impulse initiation and conduction, leading to loss of sensation at the site of application.
Rapid onset of sensory blockade within 3 to 5 minutes on mucosal surfaces.
Mucosal absorption facilitating localized effect, with potential for systemic absorption if dosed excessively.
Membrane-stabilizing properties influencing cardiac and central nervous system excitability at higher plasma levels.
Lubricating properties due to hypromellose component enhancing procedural ease during instrumentation.
Concentration-dependent protein binding influencing pharmacokinetics and dynamics.
Metabolites exhibit similar but less potent local anesthetic and toxic effects.
Capacity to cross blood-brain and placental barriers.
Sodium channel blockade in rapidly firing nerves demonstrating use-dependent pharmacology.
Dose-dependent potential for systemic neurotoxicity and cardiotoxicity if absorption is excessive.
Minimal cross-reactivity with ester-type local anesthetics reducing allergic potential.
Non-irritating to mucosal surfaces allowing safe topical administration.
Antiarrhythmic effects observed systemically but not at topical doses.

Therapeutic Or Clinical Uses

Topical anesthesia for male urethral procedures including catheterization and cystoscopy.
Topical anesthesia for female urethral instrumentation and treatment of painful urethritis.
Anesthetic lubricant for endotracheal intubation (oral and nasal) to diminish discomfort and facilitate tube passage.
Providing local mucosal anesthesia for minor urological diagnostic and therapeutic interventions.
Relief of pain and discomfort during mucosal instrumentation in hospital and outpatient settings.
Adjunct anesthesia in bronchoscopic or tracheal procedures to blunt airway reflexes.
Improvement of procedural tolerance and patient comfort during catheter placement and urethral dilation.
Facilitation of clinical examination and minor mucosal surgeries requiring topical anesthesia.
Temporary localized pain relief where injection anesthesia is impractical or contraindicated.
Use in specialized populations such as neonates and elderly with dose adjustments for local anesthesia.
Provision of lubrication and anesthesia combined in one preparation to enhance procedural efficiency.
Alternative to systemic analgesia for select mucosal analgesic indications.
Supportive anesthetic agent in diagnostic urological imaging requiring catheter placement.
Topical anesthesia prior to surgical instrumentation reducing need for injectable anesthetics.

Side Or Adverse Effects

Central nervous system effects including lightheadedness, nervousness, apprehension, dizziness, drowsiness, confusion, tinnitus, blurred or double vision, convulsions, and in severe cases, respiratory arrest.
Cardiovascular manifestations such as bradycardia, hypotension, cardiovascular collapse, and potential cardiac arrest with overdose or rapid absorption.
Rare allergic reactions including urticaria, cutaneous lesions, edema, and anaphylactoid responses.
Local irritation or discomfort at the site of application, though rare due to the non-irritant formulation.
Potential for methemoglobinemia, particularly in susceptible individuals (e.g., infants <6 months, G6PD deficiency, or concurrent oxidant exposure).
Rare reports of endotracheal tube lumen occlusion caused by dried jelly residue leading to airway obstruction.
Systemic toxicity resulting from excessive dosing or accidental intravascular administration.
Potential CNS depression or excitation symptoms with high blood levels.
Hypersensitivity reactions to preservatives or inactive ingredients (methylparaben, propylparaben).
Twitching, tremors, and convulsions as early signs of systemic lidocaine toxicity.
Numbness in areas adjacent to application that may result in inadvertent biting or injury.
Respiratory depression in severe systemic toxicity requiring emergency interventions.
Gastrointestinal symptoms such as nausea or vomiting reported infrequently.
Transient dysgeusia or abnormal taste sensation occasionally observed post-application.

Precautions

Use the lowest effective dose to minimize risk of systemic toxicity and adverse effects.
Avoid excessive dosage and short dosing intervals to prevent high plasma lidocaine levels.
Exercise caution in patients with compromised hepatic function as metabolism and clearance may be impaired.
Reduce dosage in elderly, debilitated, acutely ill, and pediatric patients, adjusting for body weight and condition.
Avoid use in patients with known hypersensitivity to amide-type local anesthetics or formulation components.
Use cautiously in presence of severe mucosal trauma or sepsis to limit rapid systemic absorption.
Monitor for signs and symptoms of methemoglobinemia in high-risk populations and discontinue if suspected.
Do not administer into the lumen of endotracheal tubes to prevent potential lumen occlusion.
Ensure proper sterilization of applicator cones to maintain aseptic technique during administration.
Be prepared for emergency management of local anesthetic systemic toxicity, including respiratory and cardiovascular support.
Inform patients about risks related to anesthesia of the mouth and throat, including aspiration and biting risks.
Advise patients to avoid ingestion of food or liquids for at least 60 minutes post oral or pharyngeal application.
Use with caution during labor and delivery, considering total lidocaine dose from all sources.
Be alert for subtle early signs of malignant hyperthermia in susceptible individuals during anesthesia procedures.
Closely monitor patients receiving concomitant oxidant drugs that increase risk of methemoglobinemia.

Warnings

Excessive dosage or too frequent administration can lead to serious systemic toxicity and high plasma levels.
Use with extreme caution in patients with sepsis or severely traumatized mucosa due to risk of rapid systemic absorption.
Avoid introducing jelly into the inner lumen of endotracheal tubes to prevent rare cases of tube occlusion.
Methemoglobinemia can occur, especially in patients with G6PD deficiency, idiopathic/methemoglobinemia, infants under 6 months, or those on oxidizing drugs.
Symptoms of methemoglobinemia may be immediate or delayed, requiring prompt discontinuation and treatment.
Serious adverse cardiovascular and CNS effects may necessitate resuscitative measures including oxygen and supportive drugs.
Patients should strictly adhere to recommended dosages and administration guidelines to avoid toxicity.
Immediate management of local anesthetic emergencies requires airway maintenance, oxygenation, circulatory support, and anticonvulsants if needed.
Potential for allergic or anaphylactoid reactions exists but is extremely rare; skin testing offers limited predictive value.
Lidocaine crosses the placental barrier; use during pregnancy only if clearly needed and under medical supervision.
Prolonged or repeated use may cause cumulative toxicities; dosage intervals should accommodate clearance times.
Use caution in patients with heart block or severe shock as lidocaine depresses cardiac conduction and contractility.
Avoid concurrent use of other lidocaine-containing products to prevent inadvertent overdose.
Endotracheal tube lubrication should not employ jelly on stylettes due to risk of tube lumen obstruction.
Failure to monitor patient vital signs post-application can delay recognition of systemic toxic effects.

Contraindication

Known hypersensitivity or allergic reactions to lidocaine, amide-type local anesthetics, or any components of the formulation.
Patients with a history of severe allergic reactions to methylparaben, propylparaben, or other preservatives in the jelly.
Use in situations where local anesthetics are contraindicated due to patient-specific risk factors or prior adverse reactions.
Avoid use in patients with congenital or idiopathic methemoglobinemia unless under close monitoring and necessity.
Patients with active infections or severe mucosal trauma at the site of intended application requiring alternative anesthetic approaches.
Known intolerance or hypersensitivity to any topical anesthetic or related amide compounds.
Patients with prior documented anaphylaxis or severe sensitivity reactions to lidocaine preparations.
Use in newborns or infants less than 6 months is contraindicated unless benefits outweigh risks with rigorous monitoring.

Drug Interactions

Concurrent use with other local anesthetics (e.g., benzocaine, bupivacaine, mepivacaine, tetracaine, prilocaine, procaine, articaine) may increase systemic toxicity risk.
Oxidizing agents such as nitrates/nitrites (nitroglycerin, nitroprusside, nitric oxide, nitrous oxide) can potentiate methemoglobinemia risk.
Antineoplastic agents including cyclophosphamide, flutamide, rasburicase, isofamide, hydroxyurea may increase oxidative stress contributing to methemoglobinemia.
Antibiotics such as dapsone, sulfonamides, nitrofurantoin, and para-aminosalicylic acid have been associated with elevated methemoglobin levels.
Antimalarials like chloroquine and primaquine may enhance methemoglobinemia when combined with lidocaine.
Anticonvulsants including phenytoin, sodium valproate, and phenobarbital could alter lidocaine metabolism and central nervous system effects.
Acetaminophen and metoclopramide may increase oxidative metabolites leading to greater methemoglobin formation.
Sulfa drugs (e.g., sulfasalazine) and quinine have potential to increase oxidative stress and methemoglobinemia risk when used with lidocaine.
Drugs that induce or inhibit hepatic cytochrome P450 enzymes may alter lidocaine metabolism, impacting plasma concentrations.
Other CNS depressants or stimulants may potentiate lidocaine's neurological and cardiovascular effects.
Concurrent administration of other topical anesthetics or systemic lidocaine formulations increases risk of cumulative toxicity.
Caution in patients on drugs that alter cardiac conduction or contractility due to additive cardiac effects.
Medications that affect plasma protein binding may influence free lidocaine concentration and toxicity potential.
Agents causing acidosis or alteration in tissue pH may affect lidocaine ionization, absorption, and action.
Significant drug interactions may necessitate dose adjustments and heightened clinical monitoring.

Preparations Of The Drug

Sterile aqueous 2% lidocaine hydrochloride jelly formulated for topical mucosal application.
Each mL contains 20 mg lidocaine HCl, methylparaben, propylparaben, hypromellose for mucoadhesion, and pH adjusted to 6.0 to 7.0 with sodium hydroxide and/or hydrochloric acid.
Supplied in sterile aluminum tubes available in 5 mL and 30 mL sizes.
Used with a sterilized plastic cone applicator for accurate and aseptic urethral administration.
Packaging: NDC 76478-479-05 (5 mL tube) and NDC 76478-479-30 (30 mL tube).
Storage at controlled room temperature (20° to 25°C / 68° to 77°F) to maintain stability.
Single-use, discard any unused portion after initial administration to maintain sterility.
Formulation designed to maximize mucosal contact and reduce drying during procedures, preventing residue-related complications.
No combined formulations; Xylocaine Jelly is a monotherapy topical anesthetic.
Preservative content minimizes microbial contamination risk during multi-use within sterile environment.
Compatible with standard sterilization methods for applicators (boiling, gas, or cold sterilization).
Lubrication and anesthetic properties combined to facilitate clinical procedures such as catheterization and intubation.
Labeling includes clear dosing instructions, maximum dose warnings, and storage conditions per FDA guidelines.
Manufactured and distributed by Oak Pharmaceuticals, Inc. under strict pharmaceutical quality control.