Lidocaine and Lignocaine Are the Same Drug
Lidocaine and lignocaine are identical medications—lignocaine is simply the former British Approved Name (BAN) for the drug now universally known as lidocaine. 1 There is no difference in dosage, usage, efficacy, or safety between these two names; they refer to the exact same chemical compound.
Nomenclature History
- Lignocaine was the original name used primarily in the United Kingdom and Commonwealth countries 1
- Lidocaine is the International Nonproprietary Name (INN) and United States Adopted Name (USAN), now the globally accepted standard 1
- The drug was originally marketed as Xylocaine® when approved by the FDA in 1948 1
- Modern medical literature and guidelines use "lidocaine" exclusively, though older British publications may reference "lignocaine" 1
Clinical Applications and Dosing
Since these are the same drug, all dosing recommendations apply equally regardless of which name is used:
For Cardiac Arrhythmias (Ventricular Tachycardia)
- Initial bolus: 1-3 mg/kg IV (or 100 mg bolus in cardiac arrest, repeatable after 5-10 minutes) 1
- Maintenance infusion: 2-4 mg/min 1
- First-line agent for ventricular tachycardia but has no effect on supraventricular tachycardia 1
For Postoperative Pain Management
- Loading dose: Maximum 1.5 mg/kg over 10 minutes 1
- Maintenance infusion: Maximum 1.5 mg/kg/hour for no longer than 24 hours 1
- Absolute maximum: 120 mg/hour regardless of patient weight 1
- Use ideal body weight for calculations, not actual body weight 1, 2
- Contraindicated in patients weighing <40 kg 1
For Local Infiltration Anesthesia
- Without epinephrine: Maximum 4.5 mg/kg 2, 3, 4
- With epinephrine: Maximum 7.0 mg/kg 2, 3, 4
- Pediatric dosing requires 30% reduction in infants <6 months 2
Critical Safety Considerations
The narrow therapeutic window makes toxicity a significant concern regardless of which name you use:
- Toxic effects include perioral numbness, drowsiness, muscular twitching, seizures, and at severe levels, cardiac depression 1
- Lipid emulsion 20% must be readily available wherever IV lidocaine/lignocaine is administered 1
- Never combine IV administration with regional nerve blocks within the same timeframe 1
- Patients receiving IV infusions outside the operating room should be monitored in a high-dependency unit 1
Common Pitfall to Avoid
Do not confuse the nomenclature difference with a clinical difference. If you encounter "lignocaine" in older British literature or formularies, apply the exact same dosing, contraindications, and monitoring protocols as you would for "lidocaine." 1, 3