Local Anesthetics

Question 1

Lidocaine Class

Answer 1

Amide local anesthetic

Question 2

Lidocaine Use

Answer 2

Peripheral nerve block, induction, neuraxial anesthesia, topical anesthesia

Question 3

Lidocaine MOA

Answer 3

reversibly blocks voltage gated sodium channels in neurons

Question 4

Lidocaine Dose

Answer 4

Max dose 5mg/kg, total 350mg

Question 5

Lidocaine Pharmacokinetics

Answer 5

Onset = fast 
Potency = intermediate 
DOA = intermediate, long with epi 
Metabolized by liver CYP1A2 & CYP1A4 liver
Eliminated by kidneys

Question 6

Lidocaine Contraindications

Answer 6

Amide allergy

Question 7

Lidocaine Considerations

Answer 7

Adverse effects = LAST; dizziness, tinnitus, tremors, convulsion, hypotension, cardiac arrest, will see CNS toxicity before CV toxicity less likely for CV event

Amide LA have a higher risk of LAST than ester LA due to rapid absorption from hepatic metabolism

Risk for acquired methemoglobinemia

Epinephrine can be added to block as a vasoconstrictor to reduce risk of toxicity

Question 8

Bupivacaine Class

Answer 8

Amide Local Anesthetic

Question 9

Bupivacaine Use

Answer 9

Peripheral nerve block, neuraxial anesthesia, topical anesthesia

Question 10

Bupivacaine MOA

Answer 10

reversibly blocks voltage gated sodium channels in neurons, preventing depolarization

Question 11

Bupivacaine Dose

Answer 11

Max dose 2mg/kg, total 175mg

Question 12

Bupivacaine Pharmacokinetics

Answer 12

Onset = slow
Potency = high 
DOA = long, longer with epi 
Metabolized = liver 
Eliminated = kidneys

Question 13

Bupivacaine Contraindications

Answer 13

Amide allergy

Question 14

Bupivacaine Considerations

Answer 14

Adverse effects = LAST; dizziness, tinnitus, tremors, convulsion, hypotension, cardiac arrest

Epinephrine can be added to block as a vasoconstrictor to reduce risk of toxicity

Amide LA have a higher risk of LAST than ester LA due to rapid absorption from hepatic metabolism

Will see cardiotoxicity around the same time as CNS toxicity, high risk for CV event

Question 15

Chloroprocaine Class

Answer 15

Ester local anesthetic

Question 16

Chloroprocaine Use

Answer 16

Peripheral nerve block, neuraxial anesthesia, topical anesthesia

Question 17

Chloroprocaine MOA

Answer 17

reversibly blocks voltage gated sodium channels in neurons blocking depolarization

Question 18

Chloroprocaine Dose

Answer 18

Max dose 11mg/kg, total 800mg

Question 19

Chloroprocaine Pharmacokinetics

Answer 19

Onset = fast 
Potency = low 
DOA = short, 30 - 60 min 
Metabolism = plasma pseudocholinesterase 
Elimination = kidney

Question 20

Chloroprocaine Contraindications

Answer 20

Plasma pseudocholinesterase deficiency

Ester allergy

Question 21

Chloroprocaine Considerations

Answer 21

Adverse effects = LAST; dizziness, tinnitus, tremors, convulsion, hypotension, cardiac arrest

Epinephrine can be added to block as a vasoconstrictor to reduce risk of toxicity

Amide LA has a higher likelihood of allergy compared to amide LA from PABA cross reactivity within class, use an amide if allergy