Lidocaine

Amide-type local anaesthetic and class Ib antiarrhythmic (systemic use, codes C01BB01 and N01BB02)

ATC code: C01BB01

Brand names: Xylocaine

Updated 24 Sep 2026 · Methodology

Indications

Local anaesthesia for procedures and minor surgery

First line

The AEMPS Lidocaína Normon label gives the drug four routes: infiltration anaesthesia, intravenous regional anaesthesia, nerve block and epidural anaesthesia. Onset comes within minutes and the effect holds for an hour to an hour and a half, longer with adrenaline, because the vasoconstrictor slows absorption. The main limit is total dose rather than solution strength: lidocaine leaves the tissue for the bloodstream, and once the dose is exceeded, local anaesthetic systemic toxicity unfolds. The first signs are neurological: metallic taste, numbness around the mouth, ringing in the ears, agitation, then seizures, and only afterwards a fall in blood pressure and arrhythmia. The label warns separately that in a patient already receiving another local anaesthetic or a class Ib antiarrhythmic the toxic effects add up.

Sources

AEMPS: Ficha técnica Lidocaína Normon 50 mg/ml solución inyectable EFG (2026)

Ventricular fibrillation and cardiac arrest

Second line

In cardiac arrest with ventricular fibrillation or pulseless ventricular tachycardia the 2021 ERC advanced life support guideline places amiodarone 300 mg after the third defibrillator shock, with a repeat dose of 150 mg after the fifth. Lidocaine 100 mg appears there as the alternative when amiodarone is unavailable or a decision was made not to use it, with a further 50 mg dose. Neither drug has convincingly raised survival to hospital discharge, and both stay in the protocol for rhythm restoration rather than for a proven gain in outcome. The order of actions does not change: uninterrupted chest compression and early defibrillation give more than any antiarrhythmic.

Sources

ICD-10: I46.9 · ICD-11: MC82

Ventricular tachycardia

Second line

The label for intravenous lidocaine names two settings: ventricular arrhythmias during cardiac manipulation such as cardiac surgery, and life-threatening arrhythmias of ventricular origin, in particular during acute myocardial infarction. The 2022 guideline on ventricular arrhythmias names amiodarone as the first drug for sustained ventricular tachycardia with preserved haemodynamics and leaves lidocaine as an option when amiodarone is unavailable or unsuitable, particularly when the arrhythmia is ischaemic in origin, where its site of action works best. Prophylactic lidocaine in myocardial infarction is no longer given: that tactic lasted decades and was abandoned. The contraindications are firm: Stokes-Adams syndrome, Wolff-Parkinson-White syndrome, and severe sinoatrial, atrioventricular and intraventricular block.

Sources

ICD-10: I47.2 · ICD-11: BC71.0

Postoperative pain

Adjunct

A continuous intravenous lidocaine infusion during and after surgery belongs to multimodal analgesia regimens: the expectation is a lower opioid requirement and earlier return of bowel function. The 2018 Cochrane review pooled 68 trials and nearly 4500 participants and rated the evidence as low and very low quality: the difference in pain at 1–4 hours after surgery is small and clinically questionable, the effect is lost by 24 hours, and data on bowel recovery are heterogeneous. Adverse events were recorded sparsely in the trials, and the authors could not judge safety from them. The practical conclusion: it works as an adjunct in a well-monitored theatre where concentration and rhythm are watched, but it does not replace opioid or regional analgesia.

Sources

ICD-10: R52.0 · ICD-11: MG31.2

Marketing claims without evidence base

The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.

Chronic pain

Not recommended

Courses of intravenous lidocaine and lidocaine blocks get offered for chronic pain across a wide list: fibromyalgia, back pain, headache, pelvic pain. The Cochrane review of systemic local anaesthetics in neuropathic pain found that lidocaine beat placebo in trials and was no worse than comparator drugs, yet the effect was short, samples were small, and no trial showed lasting relief. The AEMPS Lidocaína Normon label carries no chronic pain indication. The risks with repeated dosing are not abstract: lidocaine accumulates when hepatic blood flow falls, and next to a beta blocker or a CYP1A2 inhibitor the concentration climbs further, with toxicity starting as numbness around the mouth and ringing in the ears. If a course of intravenous lidocaine was offered as treatment for chronic pain, consider seeking a second opinion.

Sources

ICD-10: R52 · ICD-11: MG30.Z

How to read tiers A–F

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit

Mechanism of action

Lidocaine blocks voltage-gated sodium channels from inside the cell. In a peripheral nerve that stops conduction of the pain impulse: thin unmyelinated pain and temperature fibres go first, thick motor fibres later. In ventricular myocardium lidocaine binds preferentially to channels in the inactivated state, so it acts more strongly on ischaemic, depolarised tissue and barely touches normal cells – hence its class Ib place. Metabolism runs in the liver through CYP1A2 and CYP3A4 with formation of the active monoethylglycinexylidide, and the half-life is about one and a half to two hours. Hepatic blood flow governs clearance, and drugs that reduce it raise lidocaine levels in the blood.

Safety

Contraindications

Hypersensitivity to lidocaine, to amide-type local anaesthetics or to any excipient
Epidural anaesthesia in marked hypotension, cardiogenic or hypovolaemic shock
Stokes-Adams syndrome
Wolff-Parkinson-White syndrome
Severe sinoatrial, atrioventricular or intraventricular block

Serious adverse effects

Local anaesthetic systemic toxicity: seizures, depressed consciousness, respiratory arrest
Cardiac arrest and severe conduction disturbance after rapid intravenous injection
Methaemoglobinaemia
Anaphylactic reactions
Total spinal block during epidural administration

Common adverse effects

Dizziness and drowsiness
Numbness around the mouth and a metallic taste
Fall in blood pressure
Bradycardia
Nausea and vomiting

Pregnancy: can you take Lidocaine?

Lidocaine crosses the placenta and is used in obstetrics for epidural anaesthesia in labour. Animal studies showed no fetal harm, but controlled studies in pregnant women are few, so the FDA label permits use when the benefit justifies the risk. A separate point is fetal bradycardia when maternal blood levels run high and after accidental intravascular injection, which is why the anaesthetist aspirates before injecting and works in fractionated doses.

Breastfeeding: can you take Lidocaine?

Lidocaine passes into breast milk in small amounts and is barely absorbed from the infant's gastrointestinal tract. After infiltration anaesthesia, a nerve block or an epidural, feeding continues. After a prolonged intravenous infusion, feeding resumes according to the mother's condition rather than a notional washout interval.

Calculate RID

Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.

Label mentions16 mentions

Verbatim lines from the interaction sections, in the language of the label

From this drug’s label

ModerateAmiodarone
«No se han llevado a cabo estudios específicos de interacciones con lidocaína y fármacos antiarrítmicos de clase III (como, por ejemplo, amiodarona), pero se recomienda tener precaución (ver sección…»
AEMPS, section 4.5 · Open on CIMA
Moderateanestésicos localesclass named in the label
«La lidocaína debe usarse con precaución en pacientes que reciban otros anestésicos locales o fármacos antiarrítmicos de clase Ib, ya que los efectos tóxicos son acumulativos.»
AEMPS, section 4.5 · Open on CIMA

From other drugs’ labels

MajorAmiodarone
«DRUG INTERACTIONS: CYP3A Substrate lidocaine Sinus bradycardia has been reported with oral amiodarone in combination with lidocaine given for local anesthesia. Monitor heart rate. A lower starting…»
FDA, section 7 · Open on DailyMed
MajorAtazanavir
«Established and Other Potentially Significant Drug Interactions: Antiarrhythmics: amiodarone, quinidine amiodarone, bepridil, lidocaine (systemic), quinidine ↑ amiodarone, bepridil, lidocaine…»
FDA, section 7 · Open on DailyMed
MajorBisoprolol
«Antiarrítmicos de Clase-I (ej. quinidina, disopiramida; lidocaína, fenitoína; flecainida, propafenona): Pueden potenciar los efectos sobre el tiempo de conducción auriculoventricular y aumentar el…»
AEMPS, section 4.5 · Open on CIMA
MajorDarunavir
«Established and Other Potentially Significant Drug Interactions: Cardiac Disorders : ranolazine, ivabradine dronedarone Other antiarrhythmics e.g. amiodarone, bepridil, disopyramide, flecainide…»
FDA, section 7 · Open on DailyMed
MajorNebivolol
«Antiarrítmicos de clase I (quinidina, hidroquinidina, cibenzolina, flecainida, disopiramida, lidocaína, mexiletina, propafenona): puede potenciarse el efecto sobre el tiempo de conducción…»
AEMPS, section 4.5 · Open on CIMA
MajorPropranolol
«Combinación no recomendada: La administración de propranolol durante la infusión de lidocaína puede aumentar la concentración plasmática de lidocaína en aproximadamente un 30%. Los pacientes que ya…»
AEMPS, section 4.5 · Open on CIMA
ModerateDarunavir
«ANTIANGINOSOS/ANTIARRÍTMICOS: Disopiramida Flecainida Lidocaína (sistémica) Mexiletina Propafenona Amiodarona Bepridilo Dronedarona Ivabradina Quinidina Ranolazina»
AEMPS, section 4.5 · Open on CIMA
ModeratePropranolol
«Drug Interactions: Caution should be exercised when administering propranolol with drugs that slow A-V nodal conduction, e.g. digitalis, lidocaine and calcium channel blockers.»
FDA, section 7 · Open on DailyMed
ModerateRitonavir
«Established and Other Potentially Significant Drug Interactions: Antiarrhythmics: disopyramide, lidocaine, mexiletine ↑ antiarrhythmics Caution is warranted and therapeutic concentration monitoring…»
FDA, section 7 · Open on DailyMed
Amiodarone
«Sustratos CYP P450 3A4: Otros medicamentos metabolizados por el citocromo P450 3A4: ejemplos de dichos medicamentos son lidocaína, sirolimus, tacrolimus, sildenafilo, fentanilo, midazolam, triazolam…»
AEMPS, section 4.5 · Open on CIMA
Ciprofloxacin
«Lidocaína: En voluntarios sanos se demostró que el uso concomitante de medicamentos conteniendo lidocaína con ciprofloxacino, un inhibidor moderado de la isoenzima CYP450 1A2, reduce el aclaramiento…»
AEMPS, section 4.5 · Open on CIMA
Nicotine
«DESCRIPCIÓN DEL EFECTO: Clorazepato, lidocaína (vía oral)»
AEMPS, section 4.5 · Open on CIMA
Propafenone
«DRUG INTERACTIONS: • Concomitant use of lidocaine may increase central nervous system side effects. ( 7.6 )»
FDA, section 7 · Open on DailyMed
Tacrolimus
«Recomendaciones relativas a la a dministración simultánea: In vitro , se ha demostrado que las siguientes sustancias son potenciales inhibidores del metabolismo de tacrólimus: bromocriptina…»
AEMPS, section 4.5 · Open on CIMA

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Frequently asked

What is Lidocaine used for?

Lidocaine is evaluated for the following indications with varying evidence strength: Local anaesthesia for procedures and minor surgery (evidence tier A), Ventricular tachycardia (evidence tier B), Ventricular fibrillation and cardiac arrest (evidence tier B). See the full indication matrix with dosing and citations above on this page.

What are the side effects of Lidocaine?

Common side effects of Lidocaine (≥ 1 in 100): Dizziness and drowsiness, Numbness around the mouth and a metallic taste, Fall in blood pressure, Bradycardia, Nausea and vomiting. See the Safety section for uncommon and serious reactions.

Is Lidocaine safe during pregnancy?

Is Lidocaine compatible with breastfeeding?

Who should not take Lidocaine?

Lidocaine is contraindicated in: Hypersensitivity to lidocaine, to amide-type local anaesthetics or to any excipient; Epidural anaesthesia in marked hypotension, cardiogenic or hypovolaemic shock; Stokes-Adams syndrome; Wolff-Parkinson-White syndrome; Severe sinoatrial, atrioventricular or intraventricular block. Full list in the Safety section.

Official sources

Direct links to regulator labels. Open in a new tab.

AEMPS / CIMA

Other drugs in this group

Meldonium, Nitroglycerin, Propafenone, Quinidine, Amiodarone, Dofetilide, Hawthorn (Crataegus monogyna / laevigata), Ranolazine