Ester linkage - shorter duration of action
Procaine
- metabolized in plasma
- hydrolyzed by butyrylcholinesterase
Amide linkage
Lidocaine
- metabolized in liver; excreted unchanged
- hydrolyzed by CYP450 (hepatic disease - toxicity)
More potent/longer duration of action/Lipophilic –> less potent/shorter duration of action/less Lipophilic
Tetracaine > Bupicaine > Ropivacaine > Lidocaine > Procaine > Mepivacaine
What can cause gangrene in tissues supplied by end areas?
Epinephrine - Vasoconstrictor
in muscle: activates b2 Rc = dilation but increase potential for toxicity
CNS adverse effects
- low conc = sleepy, lightheaded, visual/auditory disturbances
- high conc = nystagmus, muscle twitching, convulsion
(Give premedication - benzodiazepines to increase seizure threshold and decrease chances for CNS toxicity)
Heart adverse effects
- Bupivacaine - MOST cardiotoxic –> long duration
- Lidocaine - Class 1b antiarrthymic –> inc electrical stimulation threshold of ventricle, spont depol of ventricles during diastole
- Cocaine - Vasoconstriction, hypertension, cardiac arrhythmia
Which is the only local anesthetic that doesn’t block Na channels?
Cocaine
Ester linkage or amide linkage more prone to allergic rxns?
Ester linkage
Benzocaine
- poor water solubility
- TOPICAL agent (hemorrhoids, lubricant)
Bupivacaine
- long duration
- sensory block > motor block
Cocaine
- block nerve impulses
- TOPICAL anesthetic of upper resp tract
Dibucaine
TOPICAL CREAM only
Lidocaine
- amide (given if sensitive to ester)
- faster, intense, long lasting, extensive anesthesia
- antiarrythmial
Procaine
- low potency/slow onset/short duration
- ONLY USED for infiltration anesthesia
- metabolized by para-aminobenzoic acid –> inhibits action of sulfonamide antibiotics
Ester linkage - shorter duration of action
Procaine
- metabolized in plasma
- hydrolyzed by butyrylcholinesterase
Amide linkage
Lidocaine
- metabolized in liver; excreted unchanged
- hydrolyzed by CYP450 (hepatic disease - toxicity)
More potent/longer duration of action/Lipophilic –> less potent/shorter duration of action/less Lipophilic
Tetracaine > Bupicaine > Ropivacaine > Lidocaine > Procaine > Mepivacaine
What can cause gangrene in tissues supplied by end areas?
Epinephrine - Vasoconstrictor
in muscle: activates b2 Rc = dilation but increase potential for toxicity
CNS adverse effects
- low conc = sleepy, lightheaded, visual/auditory disturbances
- high conc = nystagmus, muscle twitching, convulsion
(Give premedication - benzodiazepines to increase seizure threshold and decrease chances for CNS toxicity)
Heart adverse effects
- Bupivacaine - MOST cardiotoxic –> long duration
- Lidocaine - Class 1b antiarrthymic –> inc electrical stimulation threshold of ventricle, spont depol of ventricles during diastole
- Cocaine - Vasoconstriction, hypertension, cardiac arrhythmia
Which is the only local anesthetic that doesn’t block Na channels?
Cocaine
Ester linkage or amide linkage more prone to allergic rxns?
Ester linkage
Benzocaine
- poor water solubility
- TOPICAL agent (hemorrhoids, lubricant)
Bupivacaine
- long duration
- sensory block > motor block
