Local Anesthetics and Adrenergic Drugs Flashcards
List the loss of function in order caused by local anesthetics
1) temperature/Pain
2) Touch
3) Proprioception (joint position)
4) Motor control
Which fibre is the thickest/most myelinated fibre?
a) A fibre
b) B fibre
c) C fibre
a) A fibre
Which fibre does not contain myelination?
a) A fibre
b) B fibre
c) C fibre
c) C fibre
Which amine is not present in a Ester local anesthetics
a) primary amine
b) tertiary amine
c) quaternary amine
d) secondary amine
c) quaternary amine
In amide local anesthetics, which type of amine does the R group have?
a) primary amine
b) tertiary amine
c) secondary amine
d) quaternary amine
b) Tertiary amine
What is usually the lipophilic group?
a) R group
b) ester group
c) amide
d) aromatic ring
d) aromatic ring
Summary of Structure Activity Relationship (read or try to recall)
Need a lipophilic group (aromatic ring)
Lipophilic and hydrophilic groups are linked by an amide or ester group
The hydrophilic group can be a primary, secondary, or tertiary amine
How are esters broken down in systemic circulation?
plasma esterases
Amides are broken down by a 2 processes in the liver called _____________ and _______
dealkylation and hydrolysis
True or false: injecting lidocaine with epinephrine will lengthen block duration?
True: delays redistribution
List the 4 groups of anesthetics and classify them according to the functional group of Esters or amide
1) procaine = ester
2) benzocaine = ester
3) lidocaine = amide
4) bupivacaine = amide
Which local anesthetic has a block duration based on only being in contact for it to work?
a) procaine
b) benzocaine
c) lidocaine
d) bupivacaine
b) benzocaine
Which local anesthetic has methemoglobinemia as its toxicity?
a) procaine
b) benzocaine
c) lidocaine
d) bupivacaine
b) benzocaine
Which local anesthetic has high cardiotoxicity?
a) procaine
b) benzocaine
c) lidocaine
d) bupivacaine
d) bupivacaine
How long is the block duration for lidocaine?
90-200 min
How long is the block duration of bupvacine?
180-600 min
List some adverse effects of local anesthetics?
CNS side effects: dizziness, blurred vision and tremors (often missed)
-later drowsiness, convulsions, unconsciousness, respiratory arrest
Which channel is affected by the adverse effects of local anesthetics?
a) calcium channels
b) sodium channels
c) potassium channels
d) Magnesium channels
b) sodium channnels
List some cardiovascular side effects from local anesthetics
hypotension, CVD collapse, bradycardia, cardiac arrest
What is the maximum safe number of lidocaine ampules that could be infiltrated around a large scalp wound in a 20kg, 6-year-old girl
Lidocaine max local dose = 7mg/kg
2% lidocaine in 2ml vials
- 5mL vial
a) 20kg x 7mg/kg = 140mg
b) `140mg/20mg/ml = 7 ml needed
c) 7ml/2ml per vial = 3.5 vials
What does the effector neuron release in the sympathetic nervous system?
a) acetylcholine
b) noradrenaline
c) epinephrine
c) norepinephrine
b) noradrenaline –> acts on adrenergic receptors
What neurotransmitter does the sweat gland release?
a) acetylcholine
b) noradrenaline
c) norepinephrine
d) epinephrine
a) acetylcholine (anti-cholinergic drugs stop you from sweating)
What neurotransmitter does the kidney release in conjunction with noradrenaline?
a) epinephrine
b) acetylcholine
c) dopamine
d) histamine
c) dopamine
True or false: Epinephrine is a non-selective agonist that activates alpha and beta receptors
True
What is epinephrine used for and how can it be given?
reducing blood blow (surgery, local anesthesia )
cardiac arrest
bronchial asthma
anaphylactic shock, angioedema, and severe hypotension.
can be given locally or intravenously
True or false: epinephrine crosses the blood-brain barrier
False: it doesnt
What are some major side effects of epinephrine?
mydriasis (pupil dilation), nervousness (indirect)
CVD: vasoconstriction, vasodilates skeletal muscles, systolic high blood pressure
Resp: bronchodilation
GI: decreased use
Urinary: decrease urge to urinate
Glands: sweating, pallor
Which receptor contracts vascular smooth muscle and dilates pupils?
a1 receptor
Which receptor blocks the release of noradrenaline?
a2 receptor
Which receptor pushes the heart to work harder (positive chronotrope)
(hint: only got 1 heart)
B1 receptor
What receptor is in charge of bronchodilation in the respiratory system?
B2 ( got 2 lungs)
What receptor relaxes the bladder and activates lipolysis?
B3 receptor
Phenylephrine activates
a) A1 receptors
b) A2 receptors
c) A1 + A2 receptors
d) B1 + B2 receptors
c) A1 + A2 receptors (non selective agonist)
List 3 functions of phenylephrine
- dilates pupils
- decongestant
- raise blood pressure
Which of the following drugs have a strong affinity for a2 receptors?
a) Xylometazoline
b) oxymetazoline
c) lisinopril
d) ramipril
b) oxymetazoline –> drops blood pressure if used too much
Clonidine is
a) a1 selective
b) a2 selective
c) b1 selective
d) b2selective
a) a2 selective
what is clonidine used for initially?
a) hypotensives
b) hypertensive
c) anti-cholinergic
d) anti-memetic
a) hypertensive + alcohol and nicotine withdrawal, analgesic, vasoconstriction
The side effect of clonidine?
dry mouth, drowsiness, sedation and constipation + blocks acetylcholine
is isoproterenol a beta or alpha receptor agonist?
beta receptor agonist
Which of the following drugs is a potent vasodilator, and increases cardiac output?
a) oxymetazoliine
b) isoproterenol
c) phenylephrine
d) epinephrine
b) isoproterenol
Salbutamol selects for which receptor?
a) a1
b) b1
c) a2
d) b2
d) b2 receptor
Which receptor does mirabegron select for and what is its function?
a) a1
b) b1
c) b3
d) b2
b3 –> relaxes bladder
What will occur to blood pressure if the alpha receptor is blocked (AKA administering a receptor antagonist) ?
lower blood pressure
contract pupils and nasal passages
Which drug is only selective for a1 receptors, and low affinity for a2 receptors?
a) Benedryl
b) prazosin
c) salbutamol
d) oxymetazoline
b) prazosin
side effects of prazosin?
tachycardia and hypotension
What occurs when you administer a b-receptor antagonist?
a) to the heart?
b) to the respiratory system
a) decrease cardiac output
b) bronchoconstrict
Propanolol blocks one or both beta receptors and does it cross the BBB
both receptors + crosses the BBB
What is propranolol used for?
hypertension, angina, migraine, essential tremor.
