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Clinical Pharmacology > 3) Anesthetics > Flashcards

3) Anesthetics Flashcards

1
Q

Forms of anesthesia

A
  • General
  • Balanced
  • IV sedation
  • Regional
  • Local
  • Infiltration
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2
Q

General anesthesia

A
  • Patient is unconscious

- Utilizes gaseous and IV anesthetics

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3
Q

Balanced anesthesia

A
  • Utilizes a combination of IV anesthetic agents (pentothal, midazolam, fentanyl, propofol) with an inhalation agent (e.g. isoflurane, sevoflurane, or desflurane)
  • Patient is not in a deep plant of anesthesia
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4
Q

IV sedation

A
  • Must be supplemented with local anesthetics
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5
Q

Regional anesthesia

A
  • Spinals, epidurals, axillary, brachial, popliteal, ankle

- Use local anesthetic to block a nerve root or major nerve

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6
Q

Local anesthesia

A
  • Uses local anesthetic in a “block” fashion around a peripheral nerve
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7
Q

Infiltration

A
  • Injection of local anesthetic around an area to be anesthetized, e.g. for suture placement
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8
Q

Goal of inhalation (gaseous-and volatile liquids) anesthesia

A
  • To provide unconsciousness

- Analgesia, amnesia, loss of autonomic reflexes, and skeletal muscle relaxation

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9
Q

Meyer-Overton Principle: “Membrane Fluidization Hypothesis” or the lipid solubility hypothesis

A
  • Anesthetic drug molecules are taken into the lipid matrix of the neuronal membrane
  • Cause increase in lateral pressure on ion channels thus obstructing ion exchange and excitability
  • Blocks release of neurotransmitter; ie blocks synaptic transmission as opposed to axonal transmission (as is the case with local anesthetics)
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10
Q

The primary molecular target for anesthetic agents

A
  • Synapse
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11
Q

Inhibitory neurotransmitters actions

A
  • Inhibit the transmembrane ion flow and post-synaptic neuron from firing an action potential
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12
Q

Inhibitory neurotransmitters names

A
  • Gamma-aminobutyric acid-A (GABAA ) receptor
  • Glycine
  • Serotonin (5-HT2 and 5HT3) receptors
  • Dopamine
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13
Q

Excitatory neurotransmitters actions

A
  • Increases the transmembrane ion flow

- Increases the post-synaptic neuron fire an action potential

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14
Q

Excitatory neurotransmitters names

A
  • Acetylcholine (nicotinic and muscarinic) receptors
  • Glutamate
  • N-methyl-D-aspartate (NMDA) receptors
  • Aminohydroxy-methyl-isoxazol-propionic acid (AMPA) receptors
  • Epinephrine, norepinephrine
  • Nnitrous oxide
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15
Q

Primary molecular target for anesthetic agents

A
  • GABAA receptor -chloride channel
  • Major mediator of inhibitory synaptic transmission
  • Benzodiazepines, barbiturates, etomidate, and propofol all facilitate GABA mediated inhibition( i.e. enhance the affinity of GABA receptors for GABA)
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16
Q

IV and general inhalation anesthetics activate

A
  • GABA receptors

- Increase chloride ion flux causing hyperpolarization and increased inhibition

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17
Q

Ketamine action

A
  • Blocks the neurotransmitter, glutamic acid on the receptor, NMDA (N-methyl-D aspartate.)
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18
Q

General anesthetics actions

A
  • Decrease the metabolic rate of the brain; increases cerebral blood flow and increases inter-cranial pressure
  • CNS Effects
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19
Q

General anesthetics effects of decreasing metabolic rate of the brain

A
  • Increases cerebral blood flow

- Increases inter-cranial pressure

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20
Q

General anesthetics CNS effects

A
  • Decreases electrical activity of the cerebral cortex (frontal and occipital lobes)
  • EEG changes convert from a fast, low voltage to slow waves with increased amplitude
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21
Q

Where anesthetics work

A
  • Substatntia gelatinosa
  • Thalamus
  • Reticular Formation
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22
Q

Substantia gelatinosa

A
  • CNS structure involved in pain transmission
  • Located apex of the afferent posterior horn of the gray matter of the spinal cord
  • Point where first order neurons of the spinothalamic tract synapse (the nucleus proprius being the other)
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23
Q

Anesthetic activity in the substantia gelatinosa

A
  • Many μ- and к-opioid receptors, presynaptic and postsynaptic, are found on these nerve cells (can be targeted to manage pain of distal origin)
  • C fibers terminate at this layer (cell bodies located here are part of the neural pathway conveying slowly conducting, poorly localized pain sensation)
  • A delta fibers (carrying fast, localized pain sensation) also terminate in the substantia gelatinosa, mostly via axons passing through the area of the nucleus proprius (there is communication between the two pain pathways)
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24
Q

Anesthetic activity in the thalamus

A
  • Sensory nuclei
  • Midline within the brain, situated between the cerebral cortex and midbrain
  • Function includes relaying sensory and motor signals to the cerebral cortex, along with the regulation of consciousness, sleep, and alertness
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25
Q

Anesthetic activity in the reticular formation

A
  • Part of brain stem which maintains consciousness, the sleep-wake cycle and filtering incoming stimuli to discriminate irrelevant background stimuli
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26
Q

Characteristics of good general anesthetics

A
  • Rapid pleasant induction and recovery
  • Rapid changes in the depth of anesthesia (stages)
  • Provides skeletal muscle relaxation
  • Wide margin of safety
  • Non-toxic
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27
Q

Factors affecting rate of induction (inhalation of gas and volatile liquids)

A
  • Concentration of the anesthetic (MAC)
  • Ventilation rate and depth
  • Solubility of the agent in the blood: Bl./gas part coefficient (eg. N20 vs. ether)
  • Blood flow and cardiac output
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28
Q

Minimum alveolar concentration (MAC)

A
  • The concentration of a gas at which 50% of patients fail to respond to a surgical stimulus
  • ie the potency of the agent - N20= 105% vs Forane= 1.15%
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29
Q

Malignant hyperthermia

A
  • Autosomal dominant genetic disorder

- Characterized by a rapid onset tachycardia, hypertension, muscle rigidity, hyperthermia, hyperkalemia and acidosis

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30
Q

Signs of malignant hyperthermia

A
  • Tachypnea
  • Tachycardia
  • Rapid increase in body temperature
  • Arrhythmias
  • Sweating
  • Cyanosis
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31
Q

Triggering agent of malignant hyperthermia

A
  • General anesthetic gas or neuromuscular blockers causing the release of free calcium ions from the skeletal muscle membrane
  • Results in spasm
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32
Q

Tx for malignant hyperthermia

A
  • Sodium dantrolene, USP (DantriumR) 1mg/kg
  • May repeat up to 10 mg/kg
  • Decreases Ca release from the sarcoplasmic reticulum
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33
Q

Diethyl ether

A
  • No longer used
  • Wide margin of safety
  • Dose: 2-4% of inspired air
  • Problems: flammable and explosive; irritating to mucous membranes; nephrotoxic; slow induction and emergence; recovery often resulted in nausea/vomit
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34
Q

Chloroform

A
  • No longer used
  • Hepato and nephrotoxic
  • Unpleasant odor
  • Nonflammable
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35
Q

Cyclopropane

A
  • Wide margin of safety
  • Dose: 70% of inspired air with 30% oxygen
  • Problems: flammable and explosive, nausea and vomiting; cardiac arrhythmias, occasional hypotension
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36
Q

Methoxyflurane,USP (Penthrane)

A
  • Volatile liquid, a difloro ethyl methylether (halogen)
  • Hydrocarbon anesthetics (most potent)
  • Problem: nephrotoxic (HORF - unable to conc. urine)
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37
Q

Methoxyflurane,USP (Penthrane) indications

A
  • Induction and maintenance of general anesthesia

- Used for surgery less than four hours due to the nephrotoxicity

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38
Q

Methoxyflurane,USP (Penthrane) contraindications

A
  • Impaired renal function/concomitant use of tetracycline

- Genetic susceptibility to malignant hyperthermia

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39
Q

Methoxyflurane,USP (Penthrane) dose

A
  • MAC 0.75%

- bl:gas part coeff: 12 (very soluble: slow induction and recovery (20-30 min)

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40
Q

Halothane (Fluothane)

A
  • Colorless, volatile, non-flammable liquid

- A trifloroethane

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41
Q

Halothane (Fluothane) indications

A
  • Induct/maintenance of gen anesth
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42
Q

Halothane (Fluothane) contraindications

A
  • Obstetrical anesthesia
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43
Q

Halothane (Fluothane) qualities

A
  • Rapid induction and emergence
  • bl:gas part coeff: 2.3
  • MAC= 0.75%
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44
Q

Halothane (Fluothane) dose

A
  • 1.5-4.5% in calibrated vaporizer
  • May be used in hand held vaporizer for analgesia
  • Mask induct: 4% for 10 min, then 1.5-3% for maintenance
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45
Q

Halothane (Fluothane) problems

A
  • Drug interaction with epinephrine sensitizes the myocardium to adrenergic agonists
  • Ventricular irritability: simultaneous use may cause ventricular tachycardia or fibrillation
  • Only 20% is metabolized; 80% excret. unchanged
  • Halothane Hepatitis
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46
Q

Halothane Hepatitis

A
  • 1:10,000 - 2-5 days post op
  • Nausea and vomit
  • Anorexia
  • Hypotension
  • Eosinophilia
  • No jaundice
  • Hepatic necrosis
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47
Q

Anesthetics in common use today

A
  • Nitrous Oxide: incomplete anesthetic; rapid inset and recovery
  • Desflurane (Suprane): low volatility (heated vaporizer; poor induction; coughing
  • Sevoflurane (Ultane): rapid induction; unstable in soda lime; Compound A = nephrotoxic
  • Isoflurane (Forane): medium onset and recovery
  • Enflurane (Ethrane): medium onset and recovery
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48
Q

Isoflurane, USP (Forane) indications

A
  • Induct. and maint. anes.
  • Not good for induction (causes coughing and laryngeal spasm)
  • More rapid induction than ethrane
  • Recommended induction, use IV ultra short acting Rx eg. pentothal
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49
Q

Isoflurane, USP (Forane) contraindications

A
  • Sensitivity to the halogenated agents

- Genetic suscept. to mal. hypertherm

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50
Q

Isoflurane, USP (Forane) qualities

A
  • Myocardial function is well maintained unlike other halogenated anesthetics which cause decrease CO
  • Does cause decreased BP due to peripheral vasodilation
  • MAC= 1.15%
  • bl:gas part coeff: 1.4 (ie the most insoluble)
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51
Q

Isoflurane, USP (Forane) dose

A
  • Dose at 1.5-3%
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52
Q

Desflurane, USP (Suprane)

A
  • A volatile liq anesth agent
  • MAC = 7.3%
  • Dose for induction: 3%
  • Dose for maintenance: 2.5-8.5%
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53
Q

Desflurane, USP (Suprane) problems

A
  • Due to low volatility needs a special heated vaporizer

- Due to pungent taste and odor it causes coughing and sympathomimetic effects (dose dependent increase in HR and BP)

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54
Q

Desflurane, USP (Suprane) contraindications

A
  • Not used in patients with coronary artery disease of children (laryngospasm)
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55
Q

Sevoflurane, USP (Ultane) indications

A
  • Induct. and maint. of gen. anes. at 0.5-3.0%

- MAC = 2.1%

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56
Q

Sevoflurane, USP (Ultane) problems

A
  • In closed circuit anesthesia machine the rebreather contains soda lime to absorb CO2
  • Sevo degrades in soda lima to Compund A which is metabolized in the liver to release floride ions and is nephrotoxic
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57
Q

Nitrous Oxide, USP chemistry

A
  • Dinitrogen monoxide- N20; inorganic gas
  • Colorless liquid in blue cylinders
  • Vapor pressure of 5 atm. becomes gas
  • Slightly sweet odor and taste
  • Non-irritating and non-toxic
  • Nonflammable
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58
Q

Nitrous oxide pharmacological properties

A
  • Low solubility in the blood
  • Blood:gas partition ratio is 0.47 (lowest)
  • MAC = 105% (highest) ie extremely weak only an analgesic
  • oil:gas partition ratio is 1.4
  • No biotransformation
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59
Q

Balanced anesthesia

A
  • Utilizes a combination of IV anesthetic agents (e.g. sodium pentothal, midazolam,fentanyl, or propofol) with an inhalation agent (e.g. isoflurane, sevoflurane, or desflurane)
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60
Q

IV Anesthetic agents by group

A
  • Barbiturates-rarely used
  • Benzodiazepine
  • Propofol
  • Etomidate
  • Ketamine
  • Opioids
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61
Q

Ultra short acting barbiturates

A
  • Chemically derivatives of barbituric acid (ie. 2,4,6 tri-oxy hexahydropryrimidine)
  • Thiopental sodium, USP (Pentothal): 1,1 ethyl, methylbutyl…
  • Methohexital, USP (Brevital): not a thiobarbiturate, an oxybarbiturate
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62
Q

Thiopental sodium, USP (Pentothal)

A
  • Ultra short acting barb
  • After an IV injection,
    unconscious in 10-20 sec
  • Conscious returns in 20-30 min
  • Must be given IV do not infiltrate (very alkaline solution), will cause tissue breakdown (slough)
  • Slowl metab in liver
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63
Q

Thiopental sodium, USP (Pentothal) site of action

A
  • Suppression of the reticular activating center of the brain stem
  • Not an analgesic
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64
Q

Thiopental sodium, USP (Pentothal) indications

A
  • Induction of anesthesia or as a sole anesthetic for a short procedure
  • Anticonvulsant
  • Euthanasia (lethal injection with pancuronium and potassium)
  • Truth serum
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65
Q

Thiopental sodium, USP (Pentothal) contraindications

A
  • Asthma and porphyria
  • Barbiturate may precipitate widespread demyelination of peripheral and cranial nerves resulting in pain, weakness and paralysis that may be life threatening
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66
Q

Thiopental sodium, USP (Pentothal) warning

A
  • Can cause myocard and resp. depression
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67
Q

Thiopental sodium, USP (Pentothal) dose

A
  • Generally given in a 2.5% (25 mg/ml.) or 5% solution (50 mg/ml)
  • Dose of 4-5 mg/kg BW
68
Q

Methohexital, USP (Brevital)

A
  • Shorter acting than pentothal (faster recovery)

- Less likely to cause bronchospasm

69
Q

Methohexital, USP (Brevital) DOA

A
  • Better for outpatient surgery

- Duration of 5-7 min after an IV bolus or given as a continuous IV drip

70
Q

Methohexital, USP (Brevital) dose

A
  • Generally given in a 1% solution

- Dose at 1mg/kg body weight (50-120 mg IV bolus)

71
Q

Midazolam HCl

A
  • CIV; IM/ IV/po/buccal, intranasal, syrup

- 3-4 X more potent than diazepam (Valium)

72
Q

Midazolam HCl actions

A
  • Enhances the effect of GABA on GABAa receptors; i.e. increases the frequency of opening Cl- ion channels resulting in neural inhibition
  • Dose dependent: sedation, hypnosis, anti-anxiety, amnesia, muscle relaxation, anti-convulsant
73
Q

Midazolam (Versed) indications

A
  • Preoperative sedation
  • Relieves anxiety, agitation
  • Provides amnesia of peri-operative events
  • Induction of IV anesthesia
  • Acute seizures may be used alone or with N20 and O2 (balanced anesthesia)
  • An opioid e.g. fentanyl
74
Q

Midazolam (Versed) contraindications

A
  • Allergy to the benzodiazepines

- Narrow angle glaucoma

75
Q

Midazolam (Versed) warnings

A
  • Cause respiratory depression

- Monitor patient closely

76
Q

Midazolam (Versed) qualities

A
  • Water soluble > valium
  • Shorter T1/2
  • Less active metabolites
  • More rapid elimination
  • Less irritation to veins
  • IV onset 2-5 min
77
Q

Midazolam (Versed) dose

A
  • Pre-op medication: 5 mg IM (may decrease to 1-3 mg IM in the geriatrics)
  • Conscious sedation: IV 1 mg (up to 2.5 mg) IV slow over two min
78
Q

Benzodiazepine overdose Tx

A
  • Tx with flumazenil (Romazicon) 0.2 mg IV only
79
Q

Flumazenil

A
  • Can trigger seizures in mixed overdoses and in benzodiazepine-dependent individuals
80
Q

Neurolepsis

A
  • State of reduced anxiety
  • State of quiescence with reduced motor activity
  • Indifference to their surroundings (ie cognitive dissociation)
81
Q

Neruoleptic analgesia

A
  • Not a drug, but a term

- ie: Combination of an analgesic and a sedative

82
Q

Fentanyl citrate (Sublimaze)

A
  • 0.1-0.2 mg. a strong narcotic

analgesic = to 10 mg morphine or 75 mg Demerol

83
Q

Sufentanil, Alfentanil, Remifentanil

A
  • All are high potency opiates
  • Droperidol (Inapsine) 5-10 mg. (a butrophenone) an anti-emetic, anti- adrenergic effects, decreases BP
  • Anticonvulsant; is combined with an opiates
84
Q

Dissociative anesthesia

A
  • Produces a strong feeling of dissociation from the environment
  • A state of sedation, immobility, amnesia, and analgesia
85
Q

Phencyclidine

A
  • Freq/ unpleasant hallucinations and psychological problems
86
Q

Ketamine hydrochloride, USP (KetajectR: KetalarR)

A
  • CIII

- IV/IM or intranasal only

87
Q

Ketamine hydrochloride, USP (KetajectR: KetalarR) dissociative amnesia action

A
  • NMDA (N-methyl-D-aspartate) receptor antagonist a glutamic acid receptor
  • Also binds to opioid μ receptors and muscarinic receptors, descending monoaminergic pain
88
Q

Ketamine- “Special K” CIII indications

A
  • IV Rx induction and maintaining anesthesia
  • Used in pediatrics
  • Analgesic for mod to severe pain
  • Bronchospasm, depression, chronic regional pain syndrome (CRPS-RSD)
  • Rapid-acting anti-depressant (excellent)
89
Q

Ketamine has been shown to be effective for

A
  • Depression in patients with bipolar disorder who have not responded to antidepressants
90
Q

Ketamine recreational use

A
  • Club drug po may cause “K-hole” in high doses

- Visual and auditory hallucinations, euphoria, amnesia

91
Q

Systemic reactions to ketamine

A
  • Like opioids causes an increase in ICP; elevated blood pressure, IOP, Cardiac output, and bronchodilation
  • Cardiac output and BP are well maintained along with airway reflexes and bronchodilation
92
Q

Ketamine dose

A
  • 1-2 mg/kg BW IV over 1 minute

- May repeat initial dose decrease dose by 1/2 to 1/3

93
Q

Ketamine duration

A
  • 10-15 min of sleep and anesthesia
  • With 40 min of analgesia per single dose
  • Increases BP, intraocular pressure, and cardiac output
94
Q

Ketamine problems

A
  • BB warning- 12% have emergence reactions possible
  • Unpleasant dreams
  • Hallucinations
  • Confusion, irrational behavior for a few hours
95
Q

Propofol (Diprivan) preparation

A
  • 1% emulsion IV only; (1,3 di-isopropyl phenol)
96
Q

Propofol (Diprivan) action

A
  • A short-acting, lipophilic emulsion IV general anesthetic
97
Q

Propofol (Diprivan) causes

A
  • Global CNS depression, presumably through agonism of GABAA receptors and perhaps reduced glutamatergic activity through NMDA receptor blockade
98
Q

Propofol indications

A
  • “total IV anesthesia”
  • IV short acting, sedative/hypnotic agent for the induction and maintenance of general anesthesia
  • Induction of sleep about 40 sec
  • Indicated for sedation in ICU for mechanically ventilated pts; referred to as the “milk of amnesia
99
Q

Propofol DOA

A
  • T1/2 = 1-3 min

- Very rapidly metabolized in liver

100
Q

Propofol dose

A
  • 2.0-2.5 mg/kg/hr. or a 40 mg IV bolus dose q 10 sec until asleep
101
Q

Propofol problems

A
  • Causes a significant decrease (30%) in blood pressure due to vasodiation
  • Painful on IV injection
  • May cause apnea
  • Causes a decrease in ICP and intra-ocular pressure
  • HR and cardiac output maintained
102
Q

Etomidate (Amidate) indications

A
  • IV gen anesthetic for induction and maintenance of anesthesia
103
Q

Etomidate (Amidate) advantages

A
  • Minimal cardiac and respiratory depression
    rapid loss of consciousness with no drop in BP and HR is unchanged
  • Has no analgesic effect
  • Must co-administer an opioid or a local anesthetic
104
Q

Etomidate (Amidate) problems

A
  • High incidence of pain on injection

- Myclonic activity and post–op nausea and vomiting

105
Q

Characteristics of local anesthetics

A
  • Completely reversible
  • Low systemic toxicity
  • Action confined principally to nerve tissue
  • Short onset time
  • Sufficiently long duration
  • Soluble in saline and water
  • Sterilizable with vasoconstrictor drugs
  • Compatible with vasoconstrictor drugs
  • Nonirritating to tissues
106
Q

Local anesthetic action (1)

A
  • Stabilizes nerve membran
  • Prevents Na/K exchange and prevents depolarization
  • Threshold for excitation increases with the [anesthetic]
  • Local anesthetic inhibits ability of the nerve membrane to alter its permeability to the larger sodium ion
107
Q

Local anesthetic action (2)

A
  • Non-depolarizing block
  • Prevents the generation and conduction of nerve impulses
  • Sensory greater than motor
108
Q

Progression of local anesthesia depends upon

A
  • Diameter, amount of myelination, and conduction velocity of the nerve
109
Q

Order of loss of nerve function in local anesthesia is

A
  • Pain, temperature, touch, proprioception, skeletal muscle tone
110
Q

weak bases (pKa of 8-9) may exist as

A
  • Ionized (cannot pass membranes easily)

- Non-ionized (which pass nerve membranes easily)

111
Q

There are three parts to the local anesthetic agent

A
  • Aromatic group: “lipophilic”
  • The intermediate chain
  • The amino group: “hydrophilic”
112
Q

Two anesthetic types

A
  • Ester group: metabolized by esterase

- Amide group: metabolized by amidase, ;non-microsomal enzyme system of the liver; excreted by the kidneys

113
Q

Local anesthetic allergies

A
  • More with esters
  • No cross allergenicity with the amides
  • Anaphylaxis
114
Q

Local anesthetic overdose

A
  • CNS toxicity
  • Dizziness, analgesia, numbness, visual and auditory disturbances, respiratory and cardiac collapse
  • Loss of consciousness
115
Q

Cardiovascular collapse and hypotension from local anesthetic CNS toxicity

A
  • Depresses cardiac conduction, excitability, refractoriness, contractility, and peripheral vascular resistance
116
Q

Tx of local anesthetic systemic toxicity or allergic reaction

A
  • Establish an airway and ventilate
  • Control of convulsion (IV barbiturate)
  • Circulatory collapse (IV fluids)
  • Vasopressor (epinephrine)
117
Q

Ester group

A
  • These are all isomers
  • Metabolized by plasma esterases (plasma)
  • Some are more prone to hydrolysis than others and thus have decreased half-lives
118
Q

Ester group names

A
  • Cocaine: CII
  • Tetracaine (Pontocaine)
  • Procaine (Novocain)
  • Chlorprocaine (Nesacaine
119
Q

Cocaine usage

A
  • For local anesthesia
  • Only naturally occurring local anesthetic; a shrub in the Andes Mts
  • Vasoconstrictive properties
  • Topically active
120
Q

Cocaine indications

A
  • Musocal anesthesia
121
Q

Cocaine concentrations

A
  • 4% sol (40 mg/ml) or a 10% sol (100 mg/ml)
122
Q

Cocaine duration

A
  • Short (20-60 min)
123
Q

Cocaine toxicity

A
  • High BB warning is a CNS stimulant w/high potential for abuse and dependence
124
Q

Tetracaine (Pontocaine) use

A
  • Effective topically and used for spinal or epidural anesthesia
  • Eye anesthesia(drops)
  • Dental nasal spray
125
Q

Tetracaine (Pontocaine) concentrations

A
  • 0.2-2%; this is the long acting ester
126
Q

Tetracaine (Pontocaine) dose

A
  • 1mg/kg bw (max dose 100 mg)
127
Q

Tetracaine (Pontocaine) onset

A
  • Slow (<15 min)
128
Q

Tetracaine (Pontocaine) duration

A
  • 2-3 hours (longer duration- slowly metabolized by plasma esterases)
129
Q

Tetracaine (Pontocaine) toxicity and potency

A
  • 10 times that of procaine (due to lipid solubility)
130
Q

Procaine (Novocain)

A
  • No topical effect
  • Vasodilator
  • Problem of hypersensitivity due to an amino group in the para position on the other side of the aromatic ring (para-amino benzoic acid hypersensitivity
131
Q

Procaine (Novocain) concentration

A
  • 0.25% -5%
132
Q

Procaine (Novocain) dose

A
  • 10 mg/kg bw

- eg. 50kg = 500 mg

133
Q

Procaine (Novocain) onset

A
  • Rapid (2-5 min)
134
Q

Procaine (Novocain) potency

A
  • 1/8 that of cocaine (increased if warmed)
135
Q

Procaine (Novocain) toxicity

A
  • 1/4 that of cocaine (minimal)
136
Q

Procaine (Novocain) pduration

A
  • Short (30-60 min)
137
Q

Amide group metabilism

A
  • Metabolized in the liver by hydrolysis by non- microsomal amidases
138
Q

Amide group names

A
  • Lidocaine (Xylocaine)
  • Bupivicaine (Marcaine; Sensorcaine), levobupivicaine (Chirocaine)
  • Mepivacaine (carbocaine)
  • Prilocaine (Citanest)
  • Etidocaine (Duranest)
  • Ropvicaine (Naropin)
139
Q

Lidocaine (Xylocaine)

A
  • Most popular
  • A vaso-dialator
  • No topical effect
  • Used as anti-arrhythmic
  • 64% protein bound
140
Q

Lidocaine (Xylocaine) concentrations

A
  • 0.5, 1%, and 2%
141
Q

Lidocaine (Xylocaine) dose

A
  • With epinephrine = 7 mg/kg bw

- Plain lidocaine (ie. w/o epinephrine) = 4.5 mg/kg body weight

142
Q

Lidocaine (Xylocaine) onset

A
  • Very rapid ( < 2 minutes)
143
Q

Lidocaine (Xylocaine) duration

A
  • 1-2 hours (moderate) (if epi. is used, duration is doubled.)
144
Q

Lidocaine (Xylocaine) toxicity

A
  • Comparable to procaine
145
Q

Bupivicaine (Marcaine; Sensorcaine) properties

A
  • More painful to inject than lidocaine
  • 96% protein bound
  • Longest duration of action
  • Not active topically
  • A vasodilator
146
Q

Bupivicaine (Marcaine; Sensorcaine) concentrations

A
  • 0.25%, 0.5%, and 0.75%
147
Q

Bupivicaine (Marcaine; Sensorcaine) dose

A
  • 2 mg/kg bw (max. dose 200 mg)

- May use with epi and double dose

148
Q

Bupivicaine (Marcaine; Sensorcaine) onset

A
  • Intermediate (5 min)
149
Q

Bupivicaine (Marcaine; Sensorcaine) duration

A
  • 4 hours-long (up to 12 hours with epineph; 24 hrs as analgesic.)
150
Q

Bupivicaine (Marcaine; Sensorcaine) toxicity

A
  • About that of lidocaine
151
Q

Mepivacaine (carbocaine)

A
  • Not active topically

- A vasoconstrictor

152
Q

Mepivacaine (carbocaine) concentrations

A
  • 0.5%, 1%, 1.5% and 2%
153
Q

Mepivacaine (carbocaine) dose

A
  • 7 mg/kg bw ( total max dose 400 mg)
154
Q

Mepivacaine (carbocaine) onset

A
  • Rapid (3-5 minutes)
155
Q

Mepivacaine (carbocaine) duration

A
  • Short (1 hr)
156
Q

Mepivacaine (carbocaine) potency and toxicity

A
  • Equal to that of lidocaine
157
Q

Prilocaine (Citanest)

A
  • 55% protein bound

- May cause methemoglobinemia in high doses

158
Q

Prilocaine (Citanest) onset

A
  • Rapid (<2 min)
159
Q

Prilocaine (Citanest) duration

A
  • Intermediate (1-2 hrs)
160
Q

Prilocaine (Citanest) potency

A
  • About equal to lidocaine
161
Q

Etidocaine (Duranest) properties

A
  • An amide
  • Intermed acting
  • Long duration
  • 94% protein bound
162
Q

Etidocaine (Duranest) duration

A
  • Long (5-10 hrs)
163
Q

Etidocaine (Duranest) latecny

A
  • Slower (3-5 min)
164
Q

Etidocaine (Duranest) potency

A
  • About 75% that of bupivicaine
165
Q

Ropivicaine (Naropin) properties

A
  • Another amide
  • Metabolized by the liver by aromatic hydroxylation P450
  • 94% plasma binding
  • Lipid solubility like that of bupivicaine and mepivicaine
166
Q

Ropivicaine (Naropin) indications

A
  • Local and regional anesthesia and pain management
  • Used for epidurals, brachial blocks, mainly L & D
  • Pain management: local infiltration; epidural (continuous or intermittent infusion)
  • surgical anesthesia: local or regional infiltration; epidural
167
Q

Ropivicaine (Naropin) supplied

A
  • Single dose vials of 0.2; 0.5; 0.75 and 1%

Clinical Pharmacology (4 decks)

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