Pharmacology Flashcards
Are pre- and/or post-gangionic neurons myelinated?
Pre-ganglionic are myelinated, post ganglionic are not
In general, where is the gangion and synapse located for the parasympathetic vs. sympathetic nervous systems
Parasympathetic: near the effector tissue Sympathetic: in the sympathetic chain, near the spinal cord
What are the 3 tissue types controlled by the autonomic nervous system?
- Cardiac tissue (muscle, nodes, and conduction system) 2. smooth muscle 3. glands
Contrast miosis and mydriasis. What autonomic nervous system causes each?
Miosis: pupil constriction due to contraction of the sphincter muscle, caused by parasymathetic innervation Mydriasis: pupil dialation due to contraction of the radial muscle, caused by sympathetic innervation
What are the neurotransmitters associated with the pre- and post-ganglionic synapses of the parasympathetic vs. sympathetic nervous systems?
Pre-ganglionic: ACh for both para and symp Post-ganglionic: ACh for para, Epinephrine and Norepinephrine for symp
Contrast the parasympathetic and sympathetic effects on blood vessel dilation/constriction.
Parasympathetic: weak (not significant) dilation Sympathetic: strong constriction to unnecessary tissues (skin and GI), dialation to liver and skeletal muscle
Name the peptides that sometimes coexist with ACh and NE in their respective post-ganglionic nerves.
Vasoactive intestinal peptide with ACh in parasympathetic Neuropeptide Y with NE in sympathetic
Where is ACh synthesized?
in the pre-synaptic terminal (Extra detail: after ACh is broken down in the synapse by AChE, the choline is transported back into the pre-synaptic neuron so it can be used to make more ACh.)
Where in a cholinergic synapse are nicotinic and muscarinic receptors found (if present)?
On the post-synaptic neuron
Identify the excitatory and inhibitory muscarinic receptors and contrast their effects.
M1, M3, M5: excitatory; stimulate IP3 and eventually increase intracellular Ca++ M2, M4: inhibitory; decrease cAMP, open K+ channels (hyperpolarizes the cell)
Name the 5 important molecules in the catecholamine synthesis pathway.
- tyrosine 2. L-dopa 3. dopamine 4. norepinephrine 5. epinephrine (last step only happens in adrenal medulla)
Identify the two types of nicotinic receptors, where they are found, and their general effects.
nAChRn (autonomic gangia - N for nerve) nAChRm (skeletal muscle - M for muscle) They cause stimulation and then blockade of their end tissue
What is the most important mechanism for termination of the action of NE?
Reuptake from the junctional space into the pre-synaptic nerve and storage vessels (requires ATP and Mg^2+) - Drugs like cocaine, tricyclic antidepressants, & methylphenidate inhibit this. (Impt exception: in blood vessels, excess NE is broken down by enzymes and/or diffused away.)
Describe the mechanism of reuptake blockers, and give examples (3).
They block reuptake of NE from the synpase (keeps stimulating the post-synaptic neuron) e.g.: cocaine, tricyclic antidepressants, methylphenidate
What class of drugs includes cocaine and methylphenidate?
Indirect acting sympathomimetic amines
What is the function of enzymes such as monoamine oxidase (in mitochondria) and catechol-O-methyl transferase (in cytoplasm)
Breaks down catecholamines (like NE) in synapse to terminate the effects.
what heart rate represents tachycardia? bradycardia?
tachy: 100
brady: 60
what effect do catecholamines have on action potential velocity?
increases action potential velocity. catecholamines include epinephrine and norepinephrine.
what arrhythmia is depicted here?
premature atrial contraction: the wave are normal but there is less distance between waves two and three

what arrhythmia is seen here?
supraventricular tachycardia the waves are regular but close together, really fast
what arrhythmia is seen here?
Accessory Pathway tachycardia: the delta wave is seen here which indicates that the signal has found another route to excite the ventricles before the normal path (example: WPW)

what arrhythmia is seen here?
Atrial tachycardia: there is a decreased PR interval

what arrhythmia is seen here?

atrial fibrillation: the QRS complex looks normal but there is no distinct P wave because there are too many atrial impulses

what arrhythmia is seen here?

atrial flutter: re-entry circuit that circulates in the atrium shows rapid, back-to-back atrial depolarization waves (ex. “saw-tooth” appearance)

what arrhythmia is seen here?
ventricular tachycardia: the ventricles are contracting too often so they can’t fill up all the way. therefore this lowers cardiac output.

what arrhythmia is seen here?
ventricular fibrillation with big coarse waves and small, frequent fine waves: the QRS is rapid and indistinguishable.
what is happening during ventricular fibrillation? what is the immediate treatment?
the ventricles are quivering and can’t pump enough blood to the body
CPR and defibrillate
what part of the cardiac cycle does long QT sydrome delay? what dangerous ECG pathology can this lead to?
delays repolarization. this can lead to Torsades de Pointes which can lead to ventricular tachycardia and death
whatare the three requirements for re-entry?
- unidirectioncal conduction block
- conduction time slows so the refractory tissue can recover (while other tissue is still depolarizing)
- adjacent cardiac tissue with many parallel pathways and different refractory periods
what arrhythmia is seen here?

bradycardia: distance between R peaks is extended (Hr approx 50)
what arrhythmia is seen here?

First degree heart block: fixed long PR interval
where does a heart block occur? what does it cause (in terms of heart beat)?
as the signal travels from the AV node/His-Purkinje system to the ventricles.
causes a slow and irregular heart beat
what arrhythmia is seen here?

second degree heart block type 1 (Wenckenbach): PR interval continues to get larger and larger and then the QRS is dropped
what arrhythmia is seen here?

2:1 Mobitz type 2: the PR interval is stable and the P wave arrives regularly. For every two normal beats, 1 QRS complex is dropped.
what arrhythmia is seen here?

third degree heart block: the P, QRS and T are all out of synchronization
what are the class 1a antiarrhythmics?
Quinidine
Procainamide
Disopyramide
“The Queen Proclaims Diso’s pyramid.”
name two class 1B antiarrhythmics
lidocaine
mexiletine
tocainide
phenytoin (also a seizure med)
name the two class IC antiarrhythmics
flecainamide
propafenone (also a beta blocker)
“Can I have Fries Please?”
what are class II antiarrhythmics? name three (there are 6 in FA)
beta blockers
**metoprolol, propanolol, **carvedilol
atenolol, timolol, esmolol
what do class 3 antiarrhythmics block?
they block potassium channels (ie prolong depolarization)
name 3 potassium channel blockers
amiodarone, ibutilide, dofetalide, sotalol
what do class 1 antiarrhythmics block?
sodium channels
what do class 2 antiarrhythmics block?
selective: only beta 1 receptors
non-selective: beta 1 and 2 receptors
what do class 4 antiarrhythmics block?
calcium channels
name the two calcium channel blockers
verapamil
diltiazam
what does adenosine mainly treat?
paroxysmal supraventricular tachycardia
what is used to treat bradyarrhythmias?
pacemaker
what is used to treat atrial fibrillation?
ablation, beta blockers (propanolol), calcium channel blockers (verapamil), digoxin
what are the primary indications for amiodarone?
ventricular tachycardia (with MI)
ventricular fibrillation
ventricular premature beats
Atrial fibrillation
Atrial flutter
what are the primary indications for digoxin?
PSVT, atrial fibrillation, congestive heart failure
what are the primary indications for procainamide?
WPW, PSVT, VT with MI, VF
what is the primary indication for verapamil?
PSVT
(AV reentry, Afib)
what is metoprolol used for?
hypertension mainly
also angina and CHF
what are the primary indications for propanolol?
HTN, angina, a fib, a flutter, post-MI
what are the primary indications for lidocaine?
VT with MI, VF
Which class of antiarrhythmics is best for hypertension?
II- beta blockers
Name four drugs that treat PSVT:
Adenosine, Digoxin, Procainamide, Verapamil
Name three drugs that treat atrial fibrillation:
amiodarone, digoxin, propanolol
alpha 1 receptor with G protein class?
vasoconstriction, mydriasis, intestinal and bladder sphincter muscle contraction
Gq
alpha 2 receptor with G protein class?
decreasesd sympathetic outflow (autoregulation), decreased insulin release, decreased lipolysis, increased platelet aggregation
Gi (inhibitory)
beta 1 receptors and G protein class?
incrased heart rate, increaseed contractility, increased renin release, increased lipolysis
Gs (stimulatory)
beta 2 receptor and G protein class?
vasodilation, bronchodilation, increases heart rate, increases contractility, increased lipolysis, insulin release, decreased uterine tone (tocolysis), ciliary muscle relaxation, increased aqueous humor production
Gs
M1 and G protein class?
CNS, enteric nervous system
Gq
M2 and G protein class?
decrease heart rate and contractility of the atria
Gi
M3 and G protein class?
increase exocrine gland secretions, increase gut peristalsis, increase bladder contraction, bronchoconstrition, increase pupillary sphincter muscle contracion (miosis), ciliary muscle relaxation (accomodation)
Gq
D1 and G protein class?
relaxes renal vascular smooth muscle
Gs
D2 and G protein class?
modulates transmitter release, especially in brain
Gi
V1 and G protein class?
increased vascular smooth muscle contraction
Gq
V2 and G protein class?
increased water permeability and reabsorption in the collecting tubules of kidney (V2 is found in the 2 kidneys)
Gs
Which antiarrhythmic is best for “atrial fibrillation with atrioventricular conduction via accessory pathway”
hint: WPW
procainamide
slow conduction in accessory pathway connecting atrium and ventricle
Which antiarrhythmic is best for patients with heart failure? why?
digoxin- (+) ionotroph
slows conduction, but increases contractility
how to treat Vfib (ventricular fibrillation)
life threatening!
- cardioversion
- Epi + defibrillation
- lidocaine, amiodarone, procainamide, magnesium
- treat hyperkalemia
how to treat torsades de pointes (long-QT syndrome)
pacing
magnesium
isoproterenol (B1 and B2 agonist, effects like epi)
how to treat digitalis toxicity
stop digitalis
tx: digibind
magnesium
What drug can you not give to WPW or SA/AV node dysfunction
digitalis, verapamil, diltiazem, amiodarone
what drug do you not want to give to a pt with a history of MI or structural deformity
flecainide
can induce AV block
slows conduction of the electrical impulse within the heart, decreased contractility of the muscle,
what drug can you not give to a pt with long QT interval
amiodarone, quinidine, procainamide, sotalol, ibutilide
lengthens QT interval