Medical Pharmacology: Practice Questions on Local Anesthetics

Local anesthetic pulmonary extraction:
1. from the arterial circulation
2. from the venous circulation
Propranolol (Inderal) effects on local anesthetic pulmonary extraction and clearance:
1. inhibits bupivacaine (Marcaine) extraction
2. reduces lidocaine (Xylocaine) plasma clearance
3. increases bupivacaine (Marcaine) plasma clearance
4. A & B
5. A, B & C
Local anesthetic type (ester or amide) more likely available for placental transfer:
1. Ester-type
2. Amide-type
Effect of fetal acidosis on local anesthetic accumulation in the fetus
1. enhanced accumulation
2. reduced accumulation
3. no effect on local anesthetic accumulation
Clearance: amide local anesthetic
1. rapid hydrolysis
2. hepatic mediation
3. significant renal excretion
Amide-type local anesthetics:
1. lidocaine (Xylocaine)
2. ropivacaine (Naropin)
3. dibucaine (Nupercainal, generic)
4. mepivacaine (Carbocaine)
5. all the above
Slows metabolism among the amide-type local anesthetics
1. prilocaine (Citanest)
2. ropivacaine (Naropin)
3. lidocaine (Xylocaine)
4. mepivacaine (Carbocaine)
Mechanism(s) for Ester-type local anesthetic metabolism:
1. hydrolysis by plasma cholinesterase
2. hydrolysis by hepatic cholinesterase
3. both
4. neither
Local anesthetic most rapidly metabolized by cholinesterase
1. tetracaine (pontocaine)
2. procaine (Novocain)
3. chloroprocaine (Nesacaine)
Systemic toxicity of ester-type local anesthetics:
1. directly proportional to hydrolytic rate
2. inversely proportional to hydrolytic rate
3. independent of hydrolytic rate
Factors that influence ester-type local anesthetic duration of action:
1. hepatic disease
2. injection site
3. elevated BUN
4. A & C
5. A, B & C
Effects on ester-type local anesthetic duration of action in patients with atypical plasma cholinesterase:
1. reduced duration
2. increased duration
3. no effect on duration of action
Example(s) of ester-type local anesthetics:
1. procaine (Novocain)
2. tetracaine (pontocaine)
3. cocaine
4. A & C
5. A, B & C
Factors which influence lidocaine (Xylocaine) metabolism:
1. hepatic disease
2. volatile anesthetics
3. reduced hepatic blood flow
4. A & C
5. A, B & C
Local anesthetic which may cause cyanosis secondary to reduced oxygen transport
1. lidocaine (Xylocaine)
2. bupivacaine (Marcaine)
3. mepivacaine (Carbocaine)
4. prilocaine (Citanest)
5. procaine (Novocain)
Most slowly eliminated among amide derivative local anesthetics:
1. mepivacaine (Carbocaine)
2. bupivacaine (Marcaine)
3. dibucaine (Nupercainal, generic)
4. procaine (Novocain)
Rationale for adding epinephrine to local anesthetic solutions:
1. reduced systemic absorption
2. prolongation of conduction blockade
3. higher anesthetic concentration near nerve fibers
4. all of the above
Factors influencing effectiveness of epinephrine or local anesthesia:
1. choice of local anesthesia
2. level of sensory blockade required or spinal anesthesia
3. both
4. neither
Inclusion of epinephrine in local anesthetic solutions decreases time to onset:
1. true
2. false
Toxicities associate with systemic epinephrine absorption following use of local anesthetic solutions containing epinephrine
1. arrhythmias
2. hypotensive responses
3. both
4. neither