Clinical beta

FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.

Drug Monograph

Lidocaine

USE IF: Local/regional anesthesia, VT/VF, airway anesthesia, opioid-sparing infusion

AVOID IF: High-grade heart block without pacemaker, hypersensitivity, no lipid rescue availability

Lidocaine

Amide local anesthetic; Class Ib antiarrhythmic

Local anestheticAntiarrhythmicNerve blockLAST riskICU use

Indication

Local/regional anesthesia, ventricular arrhythmias (VT/VF), airway anesthesia, opioid-sparing infusion

At a glance

INDICATION -> Local anesthesia and nerve blocks; second-line for VT/VF (ACLS)

ADULT DOSE -> Local: 4.5 mg/kg (no epi), 7 mg/kg (with epi); IV bolus: 1-1.5 mg/kg over 2-4 min

MAX DOSE -> 300 mg (no epi), 500 mg (with epi)

CONTRA -> High-grade heart block without pacemaker, hypersensitivity, unsafe dosing environment

ANTIDOTE -> Lipid Emulsion 20% (Intralipid) for LAST

Quick facts

Onset

Seconds (IV), 1-3 min (local), 5-15 min (IM)

Duration

Peak immediate (IV), 3-10 min (local). Local duration 30-120 min (no epi) or 2-4 h (with epi); IV bolus ~15-20 min.

Routes

IV, IM, SC, topical, intranasal, epidural, spinal, patch

Pregnancy

Safe (Category B context)

Renal

Usually no dose adjustment

Hepatic

Reduce dose significantly

Do not miss

Time to action: 15—45 min (SL/buccal), immediate (IV)

LAST & max cautions

  • LAST progression: perioral tingling -> seizures -> cardiac arrest.
  • Reduce infusion by ~50% after 24 h (half-life may double).

Critical risks

  • Always aspirate before injection and inject incrementally.
  • Lipid emulsion must be immediately available before any nerve block.
  • IV antiarrhythmic dose must NEVER be rapid push (use 2-4 min bolus).

Antidote

  • Lipid emulsion 20%: 1.5 mL/kg bolus -> infusion 0.25 mL/kg/min (repeat bolus if needed).

High-risk scenarios

  • Avoid epinephrine-containing solutions in end-arterial sites.
  • High-dose topical exposure.

Key interactions

  • Benzodiazepines/CNS depressants complicate toxicity management.
  • Concurrent antiarrhythmics increase cardiac risk.

Indications

Primary

  • Local/regional anesthesia (lacerations, blocks, procedures)
  • Ventricular arrhythmias (VT/VF)
  • Airway anesthesia (intubation/bronchoscopy)

Secondary

  • Perioperative IV analgesia (opioid-sparing)
  • Epidural/spinal anesthesia
  • Neuropathic pain (patch)

Other

  • Acute migraine (IV, off-label)
  • Cough suppression
  • RSI adjunct

Dosing

Standard: Local 4.5 mg/kg (no epi) or 7 mg/kg (with epi)

Max daily dose

  • Local without epinephrine: 4.5 mg/kg (max 300 mg).
  • Local with epinephrine: 7 mg/kg (max 500 mg).
  • Maximum total antiarrhythmic dose: 3 mg/kg.

Adult - PO

  • Topical/patch pathways only; no routine oral systemic dosing.

Adult - IV

  • Arrhythmia bolus: 1-1.5 mg/kg over 2-4 min.
  • Repeat: 0.5 mg/kg q5-10 min (max 3 mg/kg total).
  • Infusion: 1-4 mg/min.
  • Analgesia load: ~1.5 mg/kg over 10 min, then ~1.3-1.5 mg/kg/h.

Pediatric

  • Local: 1.5-2 mg/kg (max 4.5 mg/kg).
  • IV arrhythmia: 1 mg/kg bolus.
  • Specialist supervision required.

Renal adjustment

  • Usually no adjustment; monitor metabolites with prolonged infusion.

Hepatic adjustment

  • Reduce by ~50-75% in significant hepatic impairment.

Warnings

Clinical warnings

  • LAST is the most critical complication.
  • Cardiac toxicity (bradycardia, VT/VF, arrest).
  • Methemoglobinemia risk is rare but possible with high-dose topical exposure.
  • Accumulation risk after prolonged infusion (>24 h).
  • CNS toxicity (confusion, seizures).
  • Incorrect rapid IV bolus can precipitate collapse.

Adverse effects

  • Common: dizziness, perioral numbness, taste change, local irritation.
  • Serious: seizures, severe arrhythmia, cardiovascular collapse.

Contraindications / caution

Do not use

  • Hypersensitivity to amide anesthetics.
  • WPW syndrome / Stokes-Adams in antiarrhythmic context.
  • Severe AV block without pacemaker.
  • Severe sinoatrial node dysfunction (unless paced).
  • Epinephrine use in end-arterial sites.

Use caution / avoid high doses

  • Hepatic impairment.
  • Heart failure / low cardiac output.
  • Elderly.
  • Concurrent antiarrhythmics.
  • Seizure disorders.

Drug interactions

  • Amiodarone -> increased toxicity risk (consider dose reduction).
  • Beta-blockers -> reduced clearance.
  • CYP3A4 inhibitors -> increased levels.
  • Other antiarrhythmics -> additive cardiac depression.
  • Cimetidine -> increased levels.
  • IV phenytoin -> cardiac depression risk.

Special populations

Pediatrics

Weight-based specialist dosing; strict mg/kg calculations required.

Pregnancy

Generally safe and widely used in obstetrics.

Breastfeeding

Generally safe; interruption usually not required.

Elderly

Reduce dose and monitor CNS/cardiac effects.

Liver disease

Major dose reduction required.

Renal impairment

Usually no adjustment, but monitor with prolonged infusion.

Administration

  • IV bolus over 2-4 min (NEVER rapid push).
  • Continuous infusion via pump.
  • Aspirate before local injection.
  • Inject local anesthesia incrementally.
  • Use test dose with epinephrine where appropriate.
  • Airway routes include nebulized/spray/transtracheal techniques.
  • Epidural/spinal: preservative-free solutions only.
  • Patch: max 3 patches, 12 h on / 12 h off.

Infusion / dilution

  • Ensure lipid rescue is available before regional block or high-risk dosing.

Monitoring

  • Continuous ECG during IV use.
  • CNS signs for early toxicity detection.
  • Blood pressure.
  • Plasma levels for prolonged infusions when available.
  • Respiratory status.
  • Injection site / dermatomal spread during regional use.
  • Confirm lipid rescue availability before use.

Overdose / toxicity

STOP drug immediately -> airway + 100% oxygen -> treat as LAST emergency.

Recognition

  • Early: perioral tingling, metallic taste, tinnitus.
  • Progression: seizures -> coma -> cardiac arrest.
  • Recurrence is possible after initial stabilization.

Immediate actions

  • Benzodiazepines for seizures.
  • Lipid Emulsion 20% bolus: 1.5 mL/kg.
  • Then infusion: 0.25 mL/kg/min.
  • Treat immediately; do not delay.

Antidote

  • Lipid Emulsion 20% protocol for LAST.

Decontamination

  • Not typically relevant for parenteral LAST; follow toxicology guidance.

Escalation

  • ACLS with reduced-dose epinephrine.
  • ICU/advanced airway support as needed.

Clinical pearls

Common mistakes, resistance logic, and bedside traps

Early LAST sign

  • Circumoral tingling means STOP immediately and reassess.

Injection safety

  • Always aspirate and inject incrementally.

Rescue readiness

  • Lipid emulsion must be present BEFORE starting blocks.

Epinephrine role

  • Epinephrine extends duration and reduces systemic absorption in appropriate sites.

Ultrasound benefit

  • Ultrasound guidance can reduce LAST risk.

Injection and dose risk

  • Toxicity risk increases with intravascular injection and high-dose regional blocks.

Opioid-sparing

  • Strong opioid-sparing effect in perioperative care.

Unique antiarrhythmic role

  • Only local anesthetic with a major antiarrhythmic role.

Pharmacokinetics

  • Rapid IV onset.
  • Highly lipophilic.
  • Hepatic metabolism via CYP1A2 and CYP3A4.
  • Active metabolites (MEGX, GX).
  • Renal excretion of metabolites.
  • Half-life prolongs after infusion beyond 24 h.

Mechanism of action

  • Blocks voltage-gated sodium channels.
  • Prevents depolarization and impulse propagation -> anesthesia.
  • Class Ib antiarrhythmic suppresses ventricular ectopy.
  • Use-dependent effect is stronger in tachycardic tissue.

Common brand names

Saudi Arabia

Xylocaine · Liocaine · Rialocaine · Avocaine · Versatis

Global

Lidoderm · EMLA · Lidocaine (generic) · Lignocaine (INN)

Common trade names are curated examples only — formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.

Country practice notes

  • Widely available across GCC hospitals; essential in anesthesia, ER, and ICU practice.
  • Xylocaine is the dominant brand across Saudi Arabia and much of the Gulf.
  • UAE has broad topical and patch availability (including Versatis and local formulations).
  • Standard drug in emergency airway management, regional anesthesia, and cardiac protocols.

Saudi Arabia — confirm with local formulary.