Term
| What are the three basic structural components of all local anesthetics? |
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Definition
aromatic group ester or amide intermediate chain basic side-chain (amine portion, except benzocaine)
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Term
| What is the pKa of most local anesthetics? |
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Definition
pKa b/w 7.8 and 9.0 (weak bases) |
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Term
| How are ester-derived LA's metabolized? (What about amide-containing LA's?) |
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Definition
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Term
| What is meant by the term "differential blockade" with respect to LA's? |
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Definition
Factors favoring nerve blockade: - small-diameter
- unmyelinated
- peripheral fibers
- HI intrinsic firing rate
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Term
| Ester-derived LA's (Hint: one "i") |
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Definition
cocaine procaine benzocaine
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Term
| Amide-containing LA's (Hint: two "i"s) |
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Definition
Lidocaine Bupivacaine Ropivacaine
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Term
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Definition
ester LA vasoconstrictor medium onset, medium duration CNS stim. --> hypertension, tachycardia, arrhythmia contraindications: traumatized mucosa (avoid drug sepsis), pregnancy, chest pain, convulsions, irregular heart beat, liver disease, overactive thyroid, Tourette's, hypersensitivity
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Term
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Definition
ester LA slow-medium onset (2-5 min), short acting (1 hr) low potency rapid hydrolysis by pseudocholinesterase (plasma & tissue) --> short half-life contraindications: liver or heart disease, hypersens. to PABA, bleeding disorders, low pseudocholinesterase
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Term
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Definition
ester LA rapid onset (1 min), short acting (15-20 min) indications: pain, itching, mucous mem. anesthesia, lubricant for med devices greatest risk of contact hypersensitivity rxn hepatic metabolism contraindications: methemoglobinemia (esp. infants), inherited enz deficiency, asthma, heart disease, bac infxn
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Term
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Definition
amide LA (most common) fast onset, long lasting (active metabolites)
anesthetic, analgesic, antiarrhythmic no need for EPI vasoconstriction contraindications: class I arrhythmias, vasopressors, hypersens, liver disease, breast feeding
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Term
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Definition
amide LA long acting sensory analgesia w/o motor impairment indications: epidural, obstetrics, regional anesthesia cardiotoxic contraindications: liver disease, bleeding disorders, hyper/hypotension, kidney disease
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Term
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Definition
amide LA (like bupivacaine but less potent) sensory analgesia w/o motor impairment indications: labor, short-term pain mangmt, surgery, C-sxn, post-op pain mangmt less cardiotoxic may cause prolonged labor, neonatal toxicity, cardiac arrhythmias contraindications: liver or heart disease, allergy
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