Pharmacology

1. LOCALANESTHETICS
DR.FOUZIA

2. LOCALANESTHETICS
Definition:
“Drugs that produce reversible inhibition of initiation and propagation of
impulses in nervous and other excitable tissues when applied locally”

3. CLASSIFICATION OF LOCALANESTHETICS
Chemical classification:
A-ESTERS
Procaine
Cocaine
Tetracaine
Benzocaine

4. CLASSIFICATION OF LOCALANESTHETICS
Chemical classification:
A-AMIDES
Lignocaine /Lidocaine
Bupivacaine
Prilocaine
Ropivacaine
Articaine

5. LOCALANESTHETICS
Mechanism of action:
1-Diffusion into the nerve fiber
2-Blockade of sodium channels.

7. M.O.A OF LOCALANESTHETICS
Result of action of a local anesthetic
1-The threshold for excitation increases
2-Impulse conduction slows
3-Action potential amplitude ↓
4-Ability to generate an action potential is completely abolished

8. LOCALANESTHETICS
Order of blockade:
1-Pain
2-Temperature
3-Touch
4-Deep pressure
5-Motor
Recovery is in reverse order

9. THERAPEUTIC INDICATIONS OF LOCALANESTHESIA
1-Surface anesthesia
2-Infiltration anesthesia & field block anesthesia
3-Nerve block anesthesia
4-Spinal anesthesia
5-Epidural anesthesia
6-Used in ophthalmology
7-Used in dentistry

10. ADVERSE EFFECTS OF LOCALANESTHETICS
To ↓ the adverse effects of local anesthetics, add vasoconstrictor
adrenaline.
1-CNS effects:
Light headedness
Restlessness
Sleepiness
Auditory/visual disturbance
Metallic taste

11. ADVERSE EFFECTS OF LOCALANESTHETICS
1-CNS effects:
Tongue numbness
Muscle twitching
Nystagmus
Tonic clonic convulsions
2- CVS effects:
Vasodilatation  Hypotensive effects
Cardiac arrythmias
3-Local injury:
Neural injury