Local anesthetics

Question 1

Lidocaine, bupivacaine

Answer 1

• Amides
• MOA
• blockade of Na⁺ channels
• Effects
• slows, then blocks action potential propagation
• Clinical
• short-duration procedures
• topical, IV, infiltration, spinal, epidural, minor and major peripheral blocks
• bupivacaine for longer-duration procedures (not topically/IV)
• Kinetics, tox.
• parenteral
• lidocaine duration 1-2h, 2-4h with epi
• bupivacaine duration 3-6h
• lidocaine tox: CNS excitation, local neurotoxicity
• bupivacaine tox: CNS excitation, cardiovascular collapse

Question 2

Chloroprocaine, cocaine

Answer 2

• Esters
• MOA
• Na channel blocker
• cocaine also has sympathomimetic effects
• Effects
• like lidocaine
• Clinical
• chloroprocaine: very short procedures
• cocaine: procedures requiring high surface activity and vasoconstriction
• Kinetics, tox
• chloroprocaine: parenteral, duration 30-60min, 60-90min with epi, tox: like lidocaine
• cocaine: topical or parenteral, duration 1-2h, tox: CNS excitation, convulsions, arrythmias, hypertension, stroke