-
Which beta blockers interact with vasodilators?
- non-selective bb: propandolo, nadolol
- leads to unopposed alpha vasoconstriction with both epi and levoordefrin
- NO interaction likely iwht cardio-selective b1 or combined a & b blockers
-
Which antidepressants interact with vasodilators?
- Tricyclic & SNRI antidepressants: cause exaggerated resonse to EPI at synaptic cleft
- tricyclic: elavil, sinequan, pamelor, tofranil
- SNRI: effexor, cymbalta, pristiq, savella
- both used for pain management
- possible increased BP & HR but most still metabolized by COMT
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What is atomoxetine (Strattera)?
- NE reuptake inhibitor for ADHD
- can increase BP & HR with vasoconstrictors.
-
What is the interaction of cocaine/amphetamines and vasoconstrictors?
- NE reuptake inhibitors & presynaptic release of NE
- cardiac dysrhythmia
- inc BP
- avoid concurrent use wait at least 12 hours
-
Which drugs for parkinson's has potential interactions with vasoconstrictors?
- COMT inhibitors: tolcapone & entacapone
- used for Parkinson's pts taking Sinemet (l-dopa/carbidopa metabolism)
- exaggerated response to EPI
-
What are the vasoconstrictor interactions with pts w BPH?
- alpha blockers, phenothiazines, butyrophenones (at high doses)
- epinephrine reversal: hypotension(b2 no a1) and tachycardia(b1)
- more pronounced iwth levonordefrin than epi at low doses
- alphablockers: prazosin, terazosin
- phenothiazines: thorazine, prolixin
- butyrophenones: haldol
-
What is the protocol for pts sensitive to Epi?
- monitor BP & HR preop and 3-5 mins post injection, continue to monitor
- minimize epi, may readminister if BP & HR stable
- never use 1:50,000 concentration
- limit of 0.04mg
- never use epi impregnated retraction cord (.5mg/inch)
-
How do you calculate doses of vasoconstrictors?
- ratio concentrations represent grams per mL
- 1:100,000 = .01mg/mL or 10ug/mL (.018 mg / cartridge)
- 1:200,000 = .005mg/mL or 5ug/mL (.009 mg / cartridge)
- 1:50,000 = .02 mg/mL or 20 ug/mL (.036 mg / cartridge)
- 1 cartridge(1.8mL) of 1:100,000 epi contains .018 mg epi
- 1:20,000 (Levonordefrin (Neocobefrin) = 90 ug = .09 mg
-
What are suggested limits of epi and levonordefrin?
- epi = .05mg
- levonordefrin = .2mg (2 cartridges of 1:20,000)
-
What is felypressin?
- non-sympathomimetic amin: analogue of vasopressin (ADH)
- vasoconstriction primarily, little direct myocardium effect
- not available in US
- less adverse effects
- less hemostasis
- used for cardiac or drug interactions
- max 5 cartridges
- 0.03IU/mL
-
Describe the LA preparations.
- 1.8 mL single-dose
- Pyrogen-free distilled H20 with NACL added for osmotic balance
- range of pH (3-6) to enhance stability of epinephrine or levonordefrin
- citric acid and Na metabisulfite (antioxidant) to prevent vasoconstrictor breakdown
- methylparaben (anti-bacterial) now removed b/c allergenicity
-
Lidocaine prep
- 1948
- pKa: 7.9
- pH plain: 6.5
- pH w/VC: 5.0-5.5
- onset: 2-3 min
- half-life: 90 mins
- 2% (1:100,000 or 1:50,000)
- trade names: xylocaine, octocaine, lignospan
- lidostesim (w NE)
- novocol (w/ phenylephrine)
- xylestesin (plain)
-
Mepivacaine prep
- 1960
- pKa: 7.6
- pH plain: 4.5
- pH w/VC: 3.0-3.5
- onset: 1.5-2 min
- half-life: 1.9 hours
- 3% plain
- 2% (w 1:20,000 levo, 1:100,000 epi)
- trade names: carbocaine, isocaine, polocaine
-
Prilocaine
- 1965
- pKa: 7.9
- pH plain: 4.5
- pH w/VC: 3.0-4.0
- onset: 2-4 min
- half-life: 90 mins
- 4% plain
- 4% (1:200,000 epi)
- trade names: citanest plain/forte, prilonest, citanest (w/felypressin)
- lower lipid solubility therefore doesn't cross BBB and can have higher conc
-
Bupivacaine
- 1972
- pKa: 8.1
- pH plain: 4.5-6.0
- pH w/VC: 3.0-4.5
- onset: 6-10 min
- half-life: 2.7 hours
- highest pKa and longest half-life
- 0.5% w 1:200,000 epi
- trade name: marcaine
-
Articaine
- 1983
- pKa: 7.8
- pH w/VC: 4.4-5.4
- onset: 2-3 mins
- half-life: 30 mins
- amide anesthetic metabolized like ester
- 4% w (1:100,000 or 1:200,000)
- trade names: septocaine, astracaine, ultracain, zorcaine
-
Procaine
- 1904
- no longer available
- pKa 9.1
- onset: 6-10 mins
- half-life: 6 mins
- tradename: novocaine
-
What is topical anesthetics?
- conc of LA applied topically is typically greater than injection
- higher conc facilitates diffustion through mucous membrane
- yet increases risk of toxicity both locally and systemically
- effective only surface 2 to 3mm
- benzocaine and lidocaine base insoluble in H20
- so usually prepared in alcohol, propylene glycol, polyethlylene glycol etc.
- benzocaine (up to 200mg/ML) aerosol, gel, ointment, soln
- lidocaine (up to 50mg/mL) aerosol, gel ointment, soln
- others: cocaine (nasal intubation), tetracaine( too toxic), EMLA (eutectic mix of LA) prilocaine and lidocaine
-
Describe the order of LA duration of maxillary infiltration
- SHORTER THAN MANDIBULAR
- name-pulp-soft tissue
- priolocaine plain: 20, 90-110
- mepivacaine plain: 25, 60-90
- prilocain +epi: 40, 140
- mepivacain +levo: 50, 180-300
- lidocaine +epi: 60, 150
- articaine +epi: 60, 120-360
- bupivacaine + epi: 60, 250-540
-
Describe the order of LA duration of mandibular block
- LONGER THAN MAXILLARY
- name-pulp-soft tissue
- priolocaine plain: 55, 190
- mepivacaine plain: 40, 120-180
- prilocain +epi: 60, 220
- mepivacain +levo: 75, 180-300
- lidocaine +epi: 85, 180-300
- articaine +epi: 90, 120-360
- bupivacaine + epi: 240, 240-540
-
What LA preps are used for most procedures requireing 20-30 mins of pulpal anesthesia especially the maxilla?
- 2% Lidocaine w 1:100,000 epi max (60,170) mand (85,190)
- 2% mepivacaine w 1:20,000 levo max (50, 130) mand (75, 185)
- 4% articaine w 1:100,000 epi max (60,190) mand (90,200)
- 4% articaine w 1:200,000 epi
- Prilociane + epi max (40,140) mand (60,220)
-
Which LA preps are used for short procedures?
- 3% mepivacaine plain max (25,90) mand (40,165)
- 4% prilocaine plain max (20, 105) mand (55,190)
- L + epi max(60,170) mand (85,190)
-
Which LA preps are used for long and painful procedures?
- 0.5% bupivacaine w 1:200,000 epi max(60,340) mand(240,440)
- L + epi max(60,170) mand (85,190)
-
Which LA preps are used for surgical hemostasis?
- 2% Lidocaine with 1:50,000 epi
- less than 1/2 blood loss of 2% L + 1:100,000 epi
- 2% L and 1:80,000 epi less than 1/2 blood loss than mepivacaine plain or placebo
- but:
- incresed postop bleeding & pain
- delayed wound healing
- possible vasoconstrictor toxicity
-
What are the LA selection criteria?
- duration
- allergy
- drug interactions
-
Which LA's are class B pregnancy?
- lidocain and prilocaine
- everything else class C
-
What are the pregnancy classifications of topical anesthetics?
-
What is epinephrine pregnancy FDA class?
- C (high does)
- levonordefrin not ranked
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