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Local Anaesthetic / Antiarrhythmic (Class Ib) Pregnancy: Use with caution — used for obstetric local anaesthesia and epidural top-ups; avoid prolonged infusions

Lidocaine (IV — Anaesthesia/ICU)

Brand names: Xylocard, Lignocaine

Adult dose

Dose: Antiarrhythmic: 1–1.5 mg/kg IV bolus then 1–4 mg/min infusion; IV perioperative analgesia: 1.5 mg/kg over 10 min then 1.5–2 mg/kg/hour
Route: IV
Frequency: Bolus then continuous infusion
Max: 3 mg/kg bolus; 4 mg/min infusion
IV lidocaine infusion used for perioperative opioid-sparing analgesia and enhanced recovery (especially colorectal surgery). Also used for ventricular arrhythmias resistant to amiodarone. Max lidocaine dose (all routes): 3 mg/kg (plain), 7 mg/kg (with adrenaline).

Paediatric dose

Dose: 1 mg/kg
Route: IV
Frequency: Bolus (antiarrhythmic)
Max: 3 mg/kg
VT in children: 1 mg/kg IV bolus under specialist guidance.

Dose adjustments

Renal

Caution in renal failure — active metabolite (MEGX) accumulates. Reduce infusion rate.

Hepatic

Significant hepatic metabolism — reduce dose in hepatic failure. Risk of toxicity.

Paediatric weight-based calculator

VT in children: 1 mg/kg IV bolus under specialist guidance.

Clinical pearls

  • IV lidocaine infusion — evidence for enhanced recovery in colorectal surgery: reduces opioid requirements, earlier return of bowel function (PROSPECT guidelines)
  • LAST from IV lidocaine: treat with Intralipid 20% as per AAGBI guidelines
  • Therapeutic serum level: 1.5–5 mcg/mL; toxicity >6 mcg/mL

Contraindications

  • Sino-atrial disease
  • All degrees of AV block without pacemaker
  • Severe myocardial depression
  • Porphyria

Side effects

  • CNS toxicity (perioral tingling, tinnitus, drowsiness, seizures)
  • Cardiovascular depression (high doses)
  • Hypotension
  • Bradycardia

Interactions

  • Beta-blockers (additive cardiac depression)
  • Antiarrhythmics (additive)
  • Phenytoin (additive cardiac depression)
  • Cimetidine (reduces lidocaine clearance)

Monitoring

  • ECG (QRS widening, PR prolongation, arrhythmia)
  • BP, HR
  • Signs of CNS toxicity throughout infusion

Reference: BNFc; BNF 90; PROSPECT Guidelines (Lidocaine infusion); AAGBI LAST Guidelines 2023; ALS Guidelines. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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