Local Anesthetics Part 1 Flashcards
________ is the first local anesthetic.
cocaine
1st synthetic Ester: _________ (1905)
Procaine
1st synthetic Amide:____________ (1943)
Lidocaine
__________ is the standard to which all local anesthetics are compared.
lidocaine
Local Anesthetics are used for _________, acute and chronic pain and ___________.
- dysrhythmias
- anesthesia
Local Anesthetics are used in anesthesia for ________ Blockade, _______ anesthesia and ____________ muscle paralysis.
- ANS
- Sensory
- Skeletal
All Local Anesthetics are what type of Antiarrythmic classification?
- Class 1:Sodium Channel Blockers
Antiarrhythmic Classes:
* Class 1: _______________
* Class 2: ______________
* Class 3: ______________
* Class 4: _____________
- sodium-channel blockers
- Beta-Blockers
- Potassium-channel blockers
- Calcium-channel blockers
Miscellaneous Antiarrhythmic Drugs can include _____________, electrolytes supplements ( ______ and potassium) and ____________ compounds.
- adenosine
- magnesium
- digitalis
Pre-Op Tylenol dose is ________ mg PO.
Pre-Op Gabapentin dose is _______ mg PO.
- 1000
- 300
Pre-op dose of Ofiremev is ____ gram, if patient has OSA.
1 gram
Intra-Op: Induce GA w/ __________, use lidocaine to blunt the burn, ketamine and __________. Maintain GA with _______________ anesthetic.
- propofol
- paralytic
- volatile
Intra-Op Magnesium dose is ____ - ____ mg/kg (max ___ G) infusion over 1 hour.
- 30-60 mg/kg
- 6 grams
Intra-Op Lidocaine infusion dose is ___mg/kg infusion ___ hour.
- 1 mg/kg
- 1 hour
Intra-Op: Ondesetron, Decadron and _________ can be given as permitted by the surgeon.
- Ketoralac.
Intra-Op Ibuprofen dose is ____ to ____ mg IV over ____ mins; or PO Q__H PRN.
MAX dose is _______ mg/day.
- 200-800 mg
- 6 hours
- 3200 mg/day
Post-Op Tylenol dose is ______ mg TID
1000 mg
Post-Op: Super Mag dose is _____ mg BID or Magnesium Aspartate _______ mg TID
or Magnesium Oxide ______ mg BID
- 400 mg
- 615 mg
- 500 mg
Post Op Gabapentin dose is ______ mg ______.
- 300 mg
- TID
Post-Op Dose:
Celebrex or Advil ____ as permitted byt the surgeon.
TID
Lidocaine
* Intial Bolus: __ - __ mg/kg IV
* over ___ - __ mins
- 1-2 mg/kg over 2-4 mins
Lidocaine is an ______ LA.
Amide
Lidocaine:
* Drip: __ - __ mg/kg/hour:
* Terminate gtt within ___ - ___ hours.
- 1-2 mg/kg/hour
- terminate 12-72 hours
Lidocaine require careful monitoring of _______, hepatic and ________ dysfunciton.
- Cardiac
- Renal
Plasma Lidocaine Concentration of 1-5 mcg/ml causes
Analgesia
Plasma Lidocaine Concentration of 5-10 mcg/ml causes:
* Circum- oral numbness,
* __________
* ______ muscle twitching
* systemic ________
* ___________ depression.
- tinnitus
- skeletal
- hypotension
- Myocardial
Plasma Lidocaine Concentration of 10-15 mcg/mL causes _________ and _________.
- Seizures
- Unconsciousness
Plasma Lidocaine Concentration of 15- 25 causes _______ and _________.
- Apnea
- Coma
Plasma Lidocaine Concentration of >25 mcg/ml causes ____________ depression.
Cardiovascular Depression
Local Anesthetic Molecular Structure has a (1) _________ portion connected by a (2) ___________chain to the (3) _____________ portion.
- lipophillic
- hydrocarbon
- hydrophillic
Local Anesthetic Molecular Structure:
Bond Between _________ portion and ___________ chain classifies it as an amide or ester
- lipophillic portion
- hydrocarbon
Local Anesthetic Compostion constists of:
* ph __ (___ salt)
* Epinephrine
* __________ bisulfite.
- 6 (HCL salt)
- weak base
- Sodium
General role for differentiating Amide from Ester LA?
- Amides have 2 i’s
- Esters have 1 i.
______ ______ is the main determinant of DOA, but not the sole determinant.
Protein Binding
______ _____ is the main determinant of Potency.
Lipid Solubility
Name (3) Ester Local anesthetics
- Procaine
- Chloroprocaine
- Tetracaine
Name (6) Amide Local Anesthetics
- Lidocaine
- Prilocaine
- Mepivacaine
- Buprivacaine
- Levobupivacaine
- Ropivacaine
Procaine
potency/onset/Duration
- 1
- Slow
- 45-60 mins
Chloroprocaine
potency/onset/Duration
- 4
- Rapid
- 30-45 mins
Tetracaine
Potency/Onset/Duration
- 16
- Slow
- 60-180 mins
Lidocaine
potency/onset/duration
- 1
- rapid
- 60-120 mins
Prilocaine
potency/onset/duration
- 1
- slow
- 60-120 mins
Mepivacaine
potency/onset/duration
- 1
- slow
- 90-180 mins
Bupivacaine
potency/onset/duration
- 4
- slow
- 240-480 mins
Levobupivacaine
potency/onset/duration
- 4
- slow
- 240-480 mins
Ropivacaine
potency/onset/duration
- 4
- slow
- 240-480 mins
Name the (1) Amide Local Anesthetic that has a rapid onset
- Lidocaine
Name the (1) Ester Local Anesthetic that is rapid acting?
Chloroprocaine
What Ester Local Anesthetic has the longest duration?
- Tetracaine
Procaine pK
8.9
Chloroprocaine pK
8.7
Tetracaine pK
8.5
Lidocaine pK
7.9
Prilocaine pK
7.9
Mepivacaine pK
7.6
Bupivacaine pK
8.1
levobupivacaine pK
8.1
Ropivacaine pK
8.1
______ has the lowest pK of the base local anesthetics. (pK= __)
- mepivacaine
- 7.6
________ has the highest pK of all the local anesthetics. (pK = ___)
- Procaine
- 8.9
E 1/2 of Procaine
9 mins
E 1/2 of Chloroprocaine
7 mins
E 1/2 of Lidocaine
96 mins
E 1/2 of Prilocaine
96 mins
E 1/2 of Mepivacaine
114 mins
E 1/2 of Bupivacaine
210 mins
E 1/2 of Levobupivacaine
156 mins
E 1/2 of Ropivacaine
108
(3) Liposome Local Anesthetics are:
- Lidocaine
- Tetracaine
- bupivacaine
Liposome LA upload a ______ amount of LA into molecole and have a _______ release of LA in the _______.
- higher
- consistent
- tissue
Liposome LA have a ______ duration of action and ______ toxicity.
- prolonged
- decreased
FDA released: Bupivacaine ER (______) which can last up to ____ hours.
- Exparel
- 96 hours
LA bind to _____-gated ____ channels. They block/inhibit Na passage in _______ membranes.
- voltage- gated Sodium Channels
- nerve
Local Anesthetics:
* bind to Voltage-gated ___ channels.
* _____ Na+ passage in nerve membranes.
* Slows rate of __________.
* Does not reach _______.
* No action potential
- Na Channels
- Inhibits/blocks
- depolarization
- threshold
Some factors of LA that affect blockade:
* _____ solubility or _____ -ionized/unionized form.
* Repetively _______ nerve.
* _______ of the nerve.
- Lipid
- non-ionized
- stimulated
- Diameter
Other Sites of Action targets for LA are ______ channels, ______ Ion Channels and ____ protein- coupled receptors.
- Potassium
- calcium
- G
_____ or ___ (LAs) = MAC (Volatiles).
1 MAC should block ___ cm
- Minimum Effective Concentration (MEC)
- Cm
- 1
Mimimum Effect Concentration:
_____ fibers need _____ concentrations of LAs.
- Larger
- Higher
T/F: Sensory nerves have a higher Minimum Effective Concentration than Motor nerves 2x in diameter.
- False
Minimum Effective Concentration requires 2, preferably 3 Nodes of ______ (__ cm) blocked.
- Ranvier
- 1 cm
Minimum Effective Concentration:
* Preganglionic __ fibers (_____) are in charge of (SNS) are ________.
20
- B
- fastest
- sensory
Minimum Effective Concentration:
Myelinated ___ (medium) and ___ fibers (fastest) > Unmyelinated ___ fibers (small)
- A
- B
- C
Minimum Effective Concentration:
Pain and Temperature (touch/pressure, proprioception and motor) are Myelinated _______ and Unmyelinated ___ fibers.
20
- A-δ
- C
Minimum Effective Concentration:
Pregnancy ________ sensitivity.
20
- increased
Name the safe level to block in the throracic region? And why?
- T1-T4
- Lower and you will block diaphram and cardiac accelerators
Pharmacokinetics LA:
* Weak _______ with pKa values above physiologic _______.
* Only _____ in lipid-soluble ________ form .
- bases
- pH
- 50%
- nonionized
LA: pKa ______ to physiologic pH = most ______ OOA.
- closest
- rapid
LA:
* Intrinsic __________ activity = increases potency and DOA
* ________ = greater systemic absorption
- vasodilator
- lidocaine
LA:Factors that influence absorption:
* _________ of injection
* Dosage
* Use of ___________.
* Pharmacologic _______________ of the drug
- site
- Epinephrine
- Characteristics
Subcutaneous LA result in the _______ blood concentration.
lowest
Intravenous LA result in the _______ Blood Concentration.
- highest
LA: Pharmacologic characteristics of the drug is determine by the
_________ of _______ distribution.
- rate
- tissue
______ solubility is the primary determinant of ________.
- Lipid
- potency
Pharmacologic characteristics of the drug is determine by:
* rate of ________
* Cardiac ________
* ________ binding
- rate of clearance
- Cardiac Output
- Protein Binding
Protein binding of a LA:
% bound is _______ relatated to % plasma.
- inversely
Protein binding % of Lidocaine
70
Protein Binding % of Mepivacaine
77
Protein binding % of Bupivacaine
- 95
Metabolism of Amide LA is due to microsomal ______ in the _____.
- enzymes
- liver
Most Rapidly metabolized Amide LA.
Prilocaine
Intermediate metabolized Amide LA. (2)
- Lidocaine
- Mepivacaine
Slowest Metabolized Amide LA. (3)
- Etidocaine
- Bupivacaine
- Ropivacaine
Metabolism of Ester LA are Hydolysis by _______ enzymes in _______ > liver.
- cholinesterase
- plasma
Name the (1) Esters LA that is metabolized in the liver.
Cocaine
______ -______ acid in Ester LA is the main cause of allergic reactions
para-aminobenzoic acid
Amides are metabolized ____ than esters.
slower
LA that are First-Pass Pulmonary Extraction
- lidocaine
- bupivacaine (dose-dependent)
- prilocaine
Renal Eliminatation and Clearance of LA:
* poor water ____
* Unchanged drug in urine = __%
* Cocaine is ___ - __ %
* PABA through _______.
- solubility
- 5%
- 10 to 12%
- urine
Pregnancy causes _____ levels of plasma cholinesterase
lower
Pregnancy: Significant Transplacental transfer:
* _______, but not significant with _______/
* Ion ________
* Protein binding = rate and degree of _______.
- Amides
- esters
- ion trapping
- diffusion
Ion trapping in Fetus:
* Fetus has a _____ pH and a ___ CO2
* non-ionized turns ______ can gets trapped
* causes fetal ________.
- lower
- higher
- ionized
- bradycardia
Bupivacaine:
Protein bound/Arterial Concentration
- 95%
- 0.32
Lidocaine:
Protein bound/Arterial Concentration
- 70%
- 0.73
Prilocaine:
Protein Bound/Arterial Concentration
- 55%
- 0.85
Lidocaine is metabolized through _______ dealkylation in _____, then hydrolysis.
- Oxidative
- liver
Metabolite of Lidocaine
Xylidide
______ disease will affect metabolism and elimination of Lidocaine.
Hepatic
_______ is an LA that is also an anti-dysrhythmic.
Lidocaine
maximum infiltration dose of lidocaine is _____ mgs plain and _____ mgs w/ EPI.
- 300
- 500
_______ induced Hypertension can prolong clearance of Lidocaine.
Pregnancy
________ is the metabolite of Prilocaine that converts Hemoglobin to methemoglobin causing ______________.
- Orthotoluidine
- Methemoglobinemia
Orthotoluidine:
* converts Hgb –> Met HGB
* Prilocaine Dose: > _____ mgs
* Cause _____ d/t decreased O2 carrying capacity
* Tx: __________ Blue
- > 600 mgs
- Cyanosis
- methylene blue
Methylene Blue:
* ___ - ___ mgs/kg IV over 5 mins
* Total dose does not exceed ___ to___ mgs/kg
- 1 to 2 mgs/kgs IV
- 7 to 8 mgs/kg
Mepivacaine is similiar to Lidocaine except:
* ____ DOA
* lacks ______ activity
* ______ elimination in fetus & newborns; No OB.
- longer
- vasodilator
- prolonged
Bupivacaine:
* Metabolism: _______ hydroxylation, N-dealkylation, _____ hydrolysis and conjugation
* Protein (95%) binding site: ________ - Acid glycoprotein
- aromatic
- amide
- α1-Acid
Dibucaine
* Metabolism: ______
* MOA: inhibits the activity of normal butyrylcholinesterase (_________ ___________) by more than ___%.
- liver
- plasma cholinesterase
- 70%
Procaine
* Metabolite: _______, excreted unchanged in _______.
- PABA
- urine
Chloroprocaine
* Metabolism: ________ ____________ (3.5x faster)
* Pregnancy __________ plasma cholinesterase by ____%
- plasma cholinesterase
- decreases
- 19%
Tetracaine
Metabolism: _________ than procaine
slower
Hydrolysis: chloroprocaine > ________ > tetracaine
procaine
Benzocaine is unique because it is a weak ______ with a pKa of ____.
- acid
- 3.5
Benzocaine is used for ________ anesthesia of ______ membranes:
* _______ intubations, Endoscopy, TEE and __________.
- Topical
- mucous
- Tracheal Intubation
- Bronchoscopy
Benzocaine
* Onset: _______
* Duration: ____ to ____ mins
* Dose: Brief Spray (20%) = ___ to ___ mgs
- rapid
- 30 to 60 mins
- 20%
- 200-300 mgs
A critical S/E of Benzocaine is ____________.
methemoglobinemia.
Cocaine is metabolized by _______ and _____ Cholinesterase.
- Liver
- plasma
Plasma Cholinesterase is decreased in Parturient, ________, Elderly and ______ Hepatic Disease.
- Neonates
- Severe
Cocaine:
* Peak: ___ to ___ mins
* Duration: ___ minutes after peak
* Elimination by _____ (24 to 36 hours)
- 30 to 45 mins
- 60 minutes
- urine
Cocaine cautions:
* Coronary _______
* _______ dysrhythmias
* HTN
* Tachycardia
* CAD
- vasospasms
- ventricular dysrhythmias
Name the (1) LA that is a weak acid and not a weak base.
- Benzocaine
