Locaine

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Locaine

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Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Locaine

Property Description
Active Ingredients Lidocaine Hydrochloride, Adrenaline (Epinephrine)
Form Sterile Solution for Injection (Parenteral Preparation)
Pharmacological Class Local Anesthetic with Vasoconstrictor
Common Use Local or Regional Anesthesia
Origin Synthetic (Lidocaine component)

Locaine is defined as a fixed-dose combination medicinal product primarily classified as a Local Anesthetic with Vasoconstrictor. It is comprised of two principal active ingredients: Lidocaine Hydrochloride, a synthetic amide-type local anesthetic that blocks nerve signals, and Adrenaline (epinephrine), a naturally occurring sympathomimetic amine that acts as a vasoconstrictor. This combination formulation is clinically recognized for providing effective, localized pain control, making it a standard tool in various medical settings.

Locaine's Pharmacological Class and Unique Composition

The drug's classification and its composition are intrinsically linked to its intended function. Locaine is a Prescription-only Medicine (POM) supplied exclusively as an injectable solution, distinguishing it from over-the-counter topical treatments. The inclusion of Adrenaline is a key differentiating feature, as it acts to minimize the rate at which the anesthetic is absorbed into the systemic circulation. This means the pain-blocking effect is concentrated and prolonged where it is needed, which is vital for sustained procedures.

Purpose and Form

The general purpose of Locaine is to induce local or regional anesthesia to support minor procedures, such as dental work or the repair of small soft-tissue injuries. The combination is utilized for its efficacy and safety profile in providing targeted relief. The final product is supplied as a sterile aqueous solution for injection (a parenteral preparation). This form ensures precise delivery near targeted nerves or tissues, confirming its use as an agent for interventional, rather than systemic, pain management.

Regulatory References

  1. Lidocaine with Epinephrine
  2. Lidocaine + epinephrine

What side effects are possible with Locaine?

Possible Side Effects and Safety Information

Adverse reactions associated with Locaine are generally dose-related, stemming from high plasma levels due to excessive dosage, rapid absorption, or accidental intravascular injection. These effects are similar to those observed with other amide-type local anesthetics and primarily affect the Central Nervous System (CNS) and Cardiovascular System.

Serious Adverse Reactions

The most serious adverse effects are systemic and include convulsions (seizures), profound hypotension (low blood pressure), bradycardia (slow heart rate), cardiovascular collapse, and cardiac arrest. A serious, rare blood disorder called methemoglobinemia has been reported, especially in susceptible populations like infants under six months of age or patients with pre-existing cardiac or pulmonary compromise. Post-marketing reports have also documented irreversible chondrolysis (damage to joint cartilage) following unapproved intra-articular infusion of the medication.

Adverse Reaction Categories

System-Organ Class Key Adverse Reactions (Common/Uncommon)
Central Nervous System Dizziness, lightheadedness, nervousness, apprehension, confusion, blurred vision, tinnitus, twitching, tremors, drowsiness, or unconsciousness.
Cardiovascular System Bradycardia, hypotension.
Allergic Reactions Cutaneous lesions, urticaria, edema, or rare anaphylactoid reactions.

Safety Considerations and Restrictions

Dose Reduction is officially required for elderly, debilitated, acutely ill, and pediatric patients commensurate with their physical status. Locaine is contraindicated in patients with a known history of hypersensitivity to amide-type local anesthetics. Certain formulations containing preservatives are restricted from use for epidural or spinal anesthesia. The risks are proportional to the total dose administered, underscoring the requirement to use the lowest effective concentration and volume.

The overall safety profile indicates that severe risk is mitigated by strict dosage adherence and careful patient monitoring for early signs of systemic toxicity, such as restlessness, anxiety, or lightheadedness, to prevent progression to life-threatening cardiovascular or CNS events.

Overdose and Emergency Response

Locaine Overdose and When to Seek Help — Official Regulatory Information

The official overdose profile for Locaine (Lidocaine Hydrochloride with Adrenaline) is defined by the risks of systemic toxicity documented in governmental regulatory sources.

Documented Overdose Manifestations Overdose initially presents with Central Nervous System (CNS) disturbances. Early documented signs include metallic taste, dizziness, tinnitus, confusion, and a feeling of numbness in the mouth. These symptoms may progress rapidly to twitching, seizures (convulsions), and subsequent unconsciousness. Cardiovascular effects often include bradycardia and hypotension.

Severe / Life-Threatening Outcomes Serious outcomes officially documented include Respiratory Arrest, Cardiovascular Collapse, and Ventricular Fibrillation. A rare, severe complication is Methemoglobinemia, which is indicated by cyanotic skin discoloration (pale, gray, or blue-colored skin/lips).

Emergency Action and Help-Seeking Immediate medical attention must be sought for any signs of systemic toxicity or suspected Methemoglobinemia. The administration of the product must be immediately discontinued. Official guidance directs that treatment is symptomatic and supportive, requiring the immediate availability of resuscitative equipment and oxygen therapy. Continuous monitoring of vital signs is mandated during treatment. Elderly and acutely ill patients, along with infants under 6 months, are officially noted to have increased risk of toxicity.

Therapeutic Uses of Locaine

What Locaine Treats: Main Uses and Benefits

The therapeutic agent, Locaine, is generally used across therapeutic domains that involve the need for local or regional pain management. This application is relevant for easing symptoms related to physical discomfort and symptoms that create noticeable physiological strain. It is commonly used to help with acute discomfort during minor medical procedures, as well as specific, painful chronic conditions involving episodic or fluctuating manifestations.

This agent is employed for the symptomatic support associated with conditions such as post-herpetic neuralgia (PHN). This targeted relief contributes to improved comfort during periods of heightened symptoms and assists with maintaining functional stability when symptoms interfere with routine activities. The agent is used for managing discomfort related to post-herpetic pain and is relevant in clinical settings that involve acute or unstable symptom patterns. One of the main benefits is that it may help patients cope more steadily with symptom fluctuations.

“It is relevant when supportive symptom management is appropriate and contributes to easing the overall symptom load.”


Quick Fact: Supports Comfort During Episodes of Localized Pain

Regulatory References

  1. NIH MedlinePlus overview of the Lidocaine Transdermal Patch

Eligibility and Restrictions for Use

Locaine, an amide-type local anesthetic (similar to lidocaine), is widely used for pain relief, but its suitability depends on the patient's overall health and the specific formulation. A healthcare provider must assess the risks and benefits before administration.

Most healthy adults and children can safely receive Locaine for procedures like dental work, minor surgery, or pain management. The dose is typically adjusted for children, the elderly, and debilitated or acutely ill patients to minimize the risk of toxicity.


Contraindications (When Locaine is Generally Avoided)

Condition Rationale for Caution/Avoidance
Allergy/Hypersensitivity Known allergy to Locaine or other amide-type local anesthetics (e.g., lidocaine, bupivacaine).
Severe Heart Problems Conditions like severe heart block (e.g., Stokes-Adams, Wolff-Parkinson-White syndrome) without a pacemaker, or severe heart failure, due to the risk of exacerbating cardiac conduction issues.
Severe Liver Dysfunction The drug is metabolized by the liver; severe impairment can lead to drug accumulation and potential toxicity.
Application Site Avoid use on broken, infected, or significantly traumatized skin when using topical preparations.

Use with Caution

Caution is advised in patients with kidney disease, severe shock, or hypovolemia. Patients with certain inherited conditions such as methemoglobinemia or glucose-6-phosphate dehydrogenase (G6PD) deficiency may also require careful consideration, as the drug or its metabolites may increase risk. Specific formulations, especially those containing preservatives or vasoconstrictors (like epinephrine), may have additional restrictions.

What should I know about interactions with other medicines?

Locaine (Lidocaine) can interact with several other medicines and substance classes, primarily by increasing the risk of systemic toxicity or by dangerously amplifying the effects of co-administered vasoconstrictors.

Potential Drug Interactions

  • Other Local Anesthetics: The toxic effects of local anesthetics, which can affect the central nervous and cardiovascular systems, are additive. Concurrent use of Locaine with other local anesthetic agents requires careful monitoring for signs of systemic toxicity.
  • Agents that Induce Methemoglobinemia: Locaine is an oxidizing agent, and co-administration with other drugs known to induce methemoglobinemia (such as certain nitrates, nitrites, antineoplastic agents, or sulfonamides) may increase the risk of this condition, which reduces the blood’s oxygen-carrying capacity.
  • CYP450 Enzyme Inhibitors: Since Locaine is rapidly metabolized by liver enzymes, particularly CYP1A2 and CYP3A4, concurrent use of strong inhibitors of these enzymes (e.g., cimetidine or certain antiarrhythmics) may decrease Locaine's clearance, leading to elevated plasma levels and an increased risk of toxicity.

Interactions Specific to Vasoconstrictor-Containing Formulations

When Locaine is formulated with a vasoconstrictor (like Epinephrine), a different set of interactions may occur due to the vasoconstrictor’s adrenergic effects. Co-administration of these specific Locaine formulations with Monoamine Oxidase Inhibitors (MAOIs) or Tricyclic Antidepressants (TCAs) may cause severe, prolonged hypertension or cerebrovascular events. Similarly, caution is required with Ergot-type Oxytocic Drugs and certain Beta-Adrenergic Antagonists.

Mechanism of Action

How Locaine Works


Voltage-Gated Sodium Channel Modulation

Locaine primarily acts by mechanisms that influence neuronal excitation through domains involving voltage-gated sodium channels ( Na^+ channels). It binds to the inner surface of the nerve cell membrane, stabilizing the neuronal membrane and preventing the influx of sodium ions . This modification of the early molecular step prevents the initiation of action potentials, consequently reducing the conduction of impulses through the targeted nerve pathways.


Myocardial Membrane Interaction

Locaine also influences processes within the heart. It selectively blocks sodium channels in depolarized cardiac tissue, a key pathway effect that slows the rate of depolarization during the cardiac action potential. This results in altered electrophysiological parameters within the ventricles, including a reduction in the rate of phase 0 depolarization in excitable tissue.


Inflammatory Cascade Modulation

Locaine interacts with mechanisms associated with the inflammatory cascade, separate from its primary sodium channel blocking effect. It modifies signaling sequences by potentially inhibiting the activation of factors like NF-kappabeta and reducing the release of pro-inflammatory mediators, such as certain interleukins and TNF-alpha.

Dosage and Administration Information

Official Administration Guidelines

Locaine is administered strictly by parenteral injection, utilizing techniques such as infiltration or peripheral nerve block for localized anesthesia. The medicine may also be used for central neural blocks like caudal or lumbar epidurals, provided the specific formulation used is certified to be free of preservatives.


Dosing and Frequency

Dosing is highly individualized and is based on the specific procedure, the extent of the area to be treated, and the desired level of anesthesia. The maximum single dose of the Lidocaine component is strictly limited to 7 mg/kg of body weight, generally not exceeding a total of 500 mg in a single administration period. The product is intended for acute, procedural use. For continuous block techniques, subsequent maximum doses must be separated by an interval of not less than 90 minutes.


Procedural Requirements and Adjustments

Administration is required to be performed by or under the supervision of experienced clinicians in a controlled setting where resuscitative equipment is immediately available. Proper technique involves aspiration prior to and during injection and utilizing slow, incremental dosing to prevent rapid systemic exposure. Dosage adjustments are indicated for specific patient groups, including older adults, acutely ill, and pediatric patients, with the dosage adjusted commensurate with the patient’s physical condition.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Locaine


Evidence for use in Local and Regional Anesthesia

The core evidence for the combination of Lidocaine and Adrenaline (Locaine) comes from short-term Randomized Controlled Trials (RCTs) and comprehensive systematic reviews. This research was primarily conducted to evaluate the use of Locaine as a local anesthetic for minor procedures. Studies examined outcomes related to physical discomfort by measuring how quickly the numbing effect began, the depth of the anesthesia achieved, and the total time the effect lasted. This research also examined the procedural success rate and monitored outcomes related to acute pain during the procedure itself.

Studies monitored and reported measurements of the time elapsed until the onset of local numbness and the duration of the localized effect. Research has primarily explored comparative efficacy, meaning placebo-controlled evidence for this acute-use medication is less frequently summarized in regulatory overviews.


Evidence for use in Dental Procedures

Specific RCTs and subsequent meta-analyses were studied for their relevance in the oral cavity. Research in this area examined outcomes related to the intensity and variability of acute discomfort by measuring two main factors: the successful achievement of anesthesia for the tooth nerve (pulpal anesthesia) and the total duration of the numbing effect on surrounding soft tissue. Research describes success rates measured in routine procedures, but findings were observed in some studies to be mixed or inconsistent when the agent was evaluated in specific, challenging conditions, such as the presence of irreversible pulpitis.


What is Still Uncertain About Locaine

While the evidence for Locaine’s primary use is widely available, certain aspects are not fully characterized. As an agent for acute, time-limited use, long-term effects are not fully established beyond the acute recovery phase. Evidence quality varies across studies when comparing Locaine to certain newer anesthetic agents or in specific, challenging anatomical locations or patient types. Furthermore, specific sub-group findings are uncertain, and data for certain groups (such as pediatric patients or the elderly) remain insufficient in large-scale trials.

Frequently Asked Questions (FAQ)

Common questions about Locaine (FAQ)

Q: How long does it typically take for Locaine to start working?

A: Official documents and research indicate that the onset of the anesthetic effect is typically rapid. The numbing effect often begins within a few minutes after the clinician administers the injection, which is important for supporting acute procedures.

Q: What is the expected duration of Locaine's effects?

A: The official product information describes the combination formulation, which includes a vasoconstrictor, as designed to prolong the duration of the anesthetic effect. This combination helps to keep the pain-blocking effect concentrated where it is needed for a specific period.

Q: Is Locaine designed for short-term or ongoing use?

A: Locaine is officially approved and labeled only for acute, time-limited use. This means it is intended for use in specific procedures, such as minor dental work or surgical interventions, rather than as a continuous or long-term medication. Consequently, its effects beyond the acute recovery phase are not fully established in regulatory documents.

Q: What does 'contraindication' mean in the context of Locaine?

A: A 'contraindication' is a medical term used in official regulatory documents. It describes a pre-existing condition or circumstance where the medicine should generally not be used. This is because official sources indicate that the potential risks of use outweigh the potential benefits in those specific patient circumstances.

Q: Is Locaine considered a fast-acting or slow-acting medication?

A: Official regulatory documents and pharmacological data characterize the onset of action of Locaine as rapid. The purpose of this formulation is to achieve a prompt localized anesthetic effect in a clinical setting.

Q: Can Locaine be taken by adolescents or children?

A: Official regulatory information specifies that doses for pediatric patients are required to be adjusted by the clinician commensurate with the patient’s physical condition. The clinician must consider the patient's age and overall health status.

Q: What should be done if someone accidentally takes too much Locaine?

A: Official regulatory documents indicate that acute systemic toxicity is a serious, life-threatening medical event that requires immediate clinical management. Signs of high plasma levels can affect the central nervous and cardiovascular systems, underscoring the need for careful patient monitoring.

Q: Is Locaine suitable for people with chronic kidney disease?

A: Caution is advised for patients with kidney dysfunction. Regulatory information indicates this is because the drug is broken down by the liver, and problems with the kidneys can affect how the medicine is cleared from the body's system.

Q: Why is a prescription required for Locaine?

A: Locaine is classified as a Prescription-Only Medicine because its administration must be performed by or under the supervision of experienced clinicians. Regulatory requirements state that the product must be used in a controlled setting where resuscitative equipment is immediately available.

Q: What does it mean if Locaine is 'metabolized' by the liver?

A: The term 'metabolized' means that the drug is processed or broken down by the body’s natural mechanisms. For Locaine, regulatory documents state this process primarily occurs through enzymes located in the liver.

Q: Does Locaine affect blood pressure or heart rate?

A: Yes, official documents list profound hypotension (low blood pressure) and bradycardia (slow heart rate) among the serious adverse reactions observed. This highlights the importance of patient monitoring during administration.

Q: Does Locaine affect fertility or reproductive health?

A: Specific human data regarding effects on fertility is generally not included in official regulatory documents for this acute-use medicine. Information on animal reproduction studies, if available, is described in the official label.

Q: Where can a patient find the official prescribing information for Locaine?

A: Official information for the drug, including the approved label and patient guidance, is made available to the public through government repositories. These include sources such as the NIH's DailyMed or MedlinePlus.

Q: Are there any known food or drink restrictions when taking Locaine?

A: The official regulatory label lists drug-drug interactions but does not list any specific food or drink restrictions. This is typical for a medication that is administered as a sterile injection rather than swallowed.

Q: What is the risk of dependence or addiction with Locaine?

A: Official government classification indicates that Locaine is not classified as a controlled substance under the US Controlled Substances Act. This regulatory status addresses the core concern about the risk of dependence or addiction.

Q: What is the main difference between Locaine and a generic alternative?

A: Official documents define Locaine as a fixed-dose combination product. It contains the local anesthetic agent (Lidocaine) combined with a vasoconstrictor (Epinephrine), which helps prolong the local effect.

Q: What does the drug manufacturer say about Locaine's effectiveness?

A: The information summarizing effectiveness is contained within the Clinical Studies section of the official regulatory label. This section presents the results and findings of the research that support the drug's approval for its intended uses.

Q: Can Locaine affect a person's ability to drive or operate machinery?

A: Official warnings state that local anesthetics may cause transient neurological effects, such as dizziness or drowsiness. These effects may cause impairment to the ability to drive or operate machinery. Official warnings advise caution.

Q: Does Locaine have any common psychological or mood side effects?

A: The official label lists Central Nervous System effects that can be perceived as affecting mood. These include reactions such as confusion, nervousness, and apprehension.

Q: Is Locaine known to cause sun sensitivity or skin reactions?

A: Allergic reactions listed in regulatory documents include various skin reactions such as cutaneous lesions and urticaria (hives). These are generally recognized adverse effects.

Q: What are the typical instructions for missed doses of Locaine?

A: Since Locaine is only administered as an acute, procedural injection in a clinical setting by a healthcare professional, the concept of a 'missed dose' does not apply to this medication.

Q: Does Locaine interact with common medications for depression or anxiety?

A: The vasoconstrictor-containing formulation specifically warns against co-administration with Monoamine Oxidase Inhibitors (MAOIs) and Tricyclic Antidepressants (TCAs), which are major classes of these medications. This is due to potential risks associated with the vasoconstrictor component.

Q: Can Locaine be taken with or without food?

A: Since Locaine is a sterile solution for parenteral injection, it is administered directly by a clinician in a local site. Therefore, the ingestion of food or drink does not affect the drug's use or absorption.

Q: Is there a maximum time Locaine is recommended to be taken?

A: Locaine is defined for acute use in procedures. Official documents specify a minimum interval of not less than 90 minutes between subsequent maximum doses, which is relevant for continuous block techniques.

Q: Are there any specific safety warnings related to Locaine and pregnancy?

A: Official documents describe the drug’s classification during pregnancy and summarize available risk data from human or animal studies. Information is available to inform discussions with a healthcare provider.

Q: What is the general consensus on Locaine in the medical community?

A: Locaine is included on the World Health Organization’s Essential Medicines List. This inclusion and its appearance in numerous international regulatory documents indicates broad recognition of its established role as a standard tool for targeted pain relief.

Q: Are there different strengths or forms of Locaine available?

A: Regulatory labels explicitly list the available concentrations and presentations of the product. Locaine is supplied as a sterile solution for injection in various strengths and vial sizes.

Q: Can Locaine be used alongside other treatments for the same condition?

A: The official label warns against using Locaine alongside other local anesthetics due to the risk of additive systemic toxicity. This warning covers a primary concern for combination use.

Q: Is Locaine approved in countries outside of the United States?

A: Inclusion on the WHO Essential Medicines List and publication in several international government sources confirms its established regulatory approval in multiple countries outside the US.

Q: Are there any known withdrawal effects if Locaine is stopped suddenly?

A: As Locaine is not classified as a controlled substance and is used for acute, one-time procedures, withdrawal effects are not described in the official regulatory labeling.

Q: Why do people sometimes experience nausea when starting Locaine?

A: Gastrointestinal disturbances, including nausea and vomiting, are generally recognized as possible adverse reactions associated with the use of amide-type local anesthetics. These effects are usually transient and dose-related.

Q: What research is available regarding Locaine and breastfeeding?

A: Official documents describe the available data (or lack thereof) on drug levels found in human milk. They also address the potential effects, if any, on the breastfed infant.

How should Locaine be stored and disposed of?

How to Store and Dispose of Locaine?

Locaine (Lidocaine/Adrenaline Injection) must be stored and handled according to specific regulatory requirements to maintain its chemical integrity and sterility as a parenteral preparation.


Official Storage Requirements

  • Temperature: Store at controlled room temperature, typically 20 C to 25 C.
  • Prohibited Environment: Do not permit the product to freeze.
  • Protection: The vials must be protected from light and kept in the original container until the time of use.
  • Child Safety: Keep the product out of the sight and reach of children.

Handling and Disposal

Unused portions of single-dose vials must be discarded after initial use. The disposal of the product and its container must be performed in accordance with local regulatory requirements for pharmaceutical waste.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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