Indications
Lignocaine (also called Lidocaine) is a local anaesthetic, a medicine that numbs a small area of the body. Creams, gels, ointments and sprays are used to ease pain and itching from minor skin irritation, insect bites, minor burns, haemorrhoids (piles) and anal fissures, and to numb skin, mouth, throat or urethra before minor procedures. Some creams combine it with a corticosteroid to calm itching and inflammation. As an injection it is used for dental work, minor surgery and nerve blocks, and in hospital to treat certain fast, irregular heart rhythms.
How It Works
Lignocaine blocks sodium channels in nerve cell membranes. This stops nerves from sending pain signals for a while, so the treated area feels numb. In the heart, the same action calms abnormal electrical activity.
Dosage and Administration
For creams, gels and ointments, apply a thin layer to the affected area, usually up to 3 to 4 times a day, or as directed on the label. Do not use more than the label allows, cover large areas, or apply to deeply broken skin unless a doctor advises it. Wash your hands after use unless the hands are being treated. Injections are given only by a doctor or dentist, and the dose depends on the procedure and the person’s weight.
Interactions
Absorbed Lignocaine can interact with Amiodarone and other heart rhythm medicines, beta blockers such as Propranolol, and Cimetidine, which can raise its blood level. Using other local anaesthetics at the same time adds to the total dose. Tell your doctor about all medicines you use, especially before a procedure.
Contraindications
Do not use Lignocaine if you are allergic to it or to other amide-type local anaesthetics such as Bupivacaine or Prilocaine. Injections are not used in people with certain types of heart block unless a specialist decides otherwise.
Side Effects
Topical forms may cause:
- Stinging, burning, redness or itching where applied
- Temporary loss of feeling in the area
If too much is absorbed, especially from injections or large areas, it may cause dizziness, drowsiness, numbness around the mouth, ringing in the ears, blurred vision, shaking or a slow heartbeat.
Get urgent medical help for fits, fainting, a very slow or irregular heartbeat, confusion, bluish or grey skin or lips, swelling of the face or throat, or difficulty breathing.
Pregnancy and Lactation
Lignocaine is widely used for local numbing during pregnancy and childbirth when needed, but check with your doctor before using it, particularly on large areas or repeatedly. Only small amounts pass into breast milk, and normal local use is generally considered compatible with breastfeeding.
Precautions and Warnings
Use extra care in children, older people and people with liver disease, heart disease or epilepsy. After numbing the mouth or throat, do not eat or drink for about 1 hour, because you may bite your tongue or choke. Keep it away from the eyes. Products that also contain a corticosteroid should not be used on the face or for long periods unless a doctor advises it.
Overdose
Too much Lignocaine can cause fits, dangerous heart rhythm problems and breathing trouble. If someone has used far too much or a child has swallowed a gel or cream, seek emergency medical care at once.
Therapeutic Class
Amide local anaesthetic; class Ib antiarrhythmic when given by injection.
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Do not freeze. Injections are stored as directed on the pack.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.