Lidocaine, also known as lignocaine, is one of the most commonly used local anesthetic agents in medicine and dentistry.
It was discovered by Swedish chemist Nils Löfgren in 1943.
Classification
Types of Local Anesthesia:
• Topical anesthesia — (Tetracaine, Lidocaine)
• Infiltration anesthesia — (Procaine, Chloroprocaine)
• Nerve block anesthesia — (Lidocaine, Prilocaine, Bupivacaine)
• Spinal/Epidural anesthesia — (Tetracaine, Bupivacaine, Lidocaine, Articaine)
Mechanism of action:-
Lidocaine blocks voltage-gated sodium channels, preventing sodium entry and depolarization. This stops action potential generation, thereby blocking nerve impulse conduction and pain sensation.
Some of the factors affecting the activity of Local Anesthesia:
• pH of tissue
• Blood supply at injection site
• Use of vasoconstrictor
• Lipid solubility of the drug
• Dose and concentration
Clinical uses:
Dentistry,Minor surgical procedures,
obstetrics,Ophthalmology,ENT procedures,pain management,emergency medicine,diagnostic interventions.
Side effects:
Local effects: pain durjng injection, hematoma, trismus
Systemic effects:Dizziness, Drowsiness, CNS depression, allergic reactions.
Safety levels of local anesthetics
Tocic level without vasoconstrictor is 3-4.4mg/kg.
Toxic level with vasoconstrictor is 7mg/kg.
Contraindications
| Absolute Contraindications | Relative Contraindications |
|---|---|
| Myocardial infarction within 6 months | Chronic renal failure |
| Recent hepatitis A or B | Hyperthyroidism |
| Jaundice | Pregnancy (1st trimester) |
| Local infection/sepsis | Hypertension |
| Hypersensitivity to lidocaine | Malignant hyperthermia |
MBH/PS