Unit 3-Local Anesthetics

Question 1

Cocaine; benzocaine (Orajel); procaine (Novocain); tetracaine; chlorprocaine

Class

Answer 1

Ester anesthetic

Question 2

Cocaine; benzocaine (Orajel); procaine (Novocain); tetracaine; chlorprocaine

Mechanism

Answer 2

Binds reversibly to the intracellular portion of the voltage-gated sodium channel and inactivates it, and so blocks transmission of nociceptive nerve impulses.

Question 3

Cocaine; benzocaine (Orajel); procaine (Novocain); tetracaine; chlorprocaine

Uses

Answer 3

Local anesthesia

Question 4

Cocaine; benzocaine (Orajel); procaine (Novocain); tetracaine; chlorprocaine

Side effects

Answer 4

• Local: transient neurologic symptoms (basically, really bad pain), neuronal injury. Systemic (more common with long-acting local anesthetics): circumoral numbness, dizziness, tinnitis, blurred vision, CNS excitation (restlessness, agitation, seizures), followed by CNS depression (respiratory arrest, unconsciousness); hypotension; cardic toxicity with higher doses.
• Methemoglobinemia (primarily with benzocaine), allergic reactions
• Used less frequently than amides; cocaine has many side effects due to action as a CNS stimulant
• PABA allergies in esters

Question 5

Lidocaine (Xylocaine); mepivacaine; bupivacaine; ropivacaine

Class

Answer 5

Amide anesthetic

Question 6

Lidocaine (Xylocaine); mepivacaine; bupivacaine; ropivacaine

Mechanism

Answer 6

Binds reversibly to the intracellular portion of the voltage-gated sodium channel and inactivates it, and so blocks transmission of nociceptive nerve impulses.

Question 7

Lidocaine (Xylocaine); mepivacaine; bupivacaine; ropivacaine

Uses

Answer 7

Local anesthesia

Question 8

Lidocaine (Xylocaine); mepivacaine; bupivacaine; ropivacaine

Side effects

Answer 8

• Local: transient neurologic symptoms (basically, really bad pain), neuronal injury. Systemic (more common with long-acting local anesthetics): circumoral numbness, dizziness, tinnitis, blurred vision, CNS excitation (restlessness, agitation, seizures), followed by CNS depression (respiratory arrest, unconsciousness); hypotension; cardic toxicity with higher doses.
• Bupivicaine has highest cardiac toxicity potential; ropivicaine less potent than others (so larger therapeutic index)

Question 9

Transient neurological syndromes not found with which ones

Answer 9

Bupivacaine

Chlorprocaine

Question 10

Increased risk of transient neurological syndromes with which ones

Answer 10

Procaine

Mepivacaine