✅Autonomic Flashcards
Spinal roots of the parasympathetic nervous system
CN III, VII, IX, X, sacral segments of the spinal cord
M2 receptors are found in the
Heart
MOA of hemicholinium
Choline transport inhibition
MOA of Vesamicol
Inhibits actively transported vesicles for storage of ach
Moa of botulinum
Alters synaptobrevins to prevent release of ach
Spinal roots of origin of the sympathetic nervous system
T1-L5
Cholinomimetic used in bladder and bowel atony
Betanechol
MOA of betanechol
Activates muscarinic (M3 receptors)
Uses of pilocarpine
Glaucoma, sjogren’s and sicca syndrome
Notable side effect of pilocarpine
Increase salivation
What is the triad of sjogren’s syndrome?
Xerostomia
Xerophthalmia
Rheumatoid arthritis
Nm receptors are found in the
Neuromuscular end plate
MOA of varenicline
Cholinomimetic directly activating Ach nicotinic receptors (Nn and Nm)
Uses of Varenicline/nicotine
Smoking cessation
Muscarinic and similar alkaloids are found in these mushrooms responsible for a short acting form of mushroom poisoning
Inocybe and amanita muscaria
Moa of indirect acting cholinomimetics
Binds to cholinesterase and undergo prompt hydrolysis amplifying acetylcholine effects
Drug used in Tensilon test for the diagnosis of MG
Edrophonium
Edrophonium is not used for therapeutics because
It is a very short acting drug and only administered intravenously
Differentiate myasthenic from cholinergic crisis
Myasthenic crisis
Acute worsening of sx due to infection, stress or UNDERMEDICATION
Cholinergic crisis
Excessive activation of cholinoceptors due to OVERMEDICATION
How does edrophonium differentiate myasthenic from cholinergic crisis?
Improves muscle strength in myasthenic crisis
Drug used in MG
Neostigmine
Indirect cholinomimetics used for alzheimer’s
Rivastigmine
Galantamine
Donepezil
Tacrine
What are the signs and symptoms of organophosphate poisoning?
DUMB BELLS
Diarrhea
Urination
Miosis
Bronchospasm
Bradycardia Excitation (skeletal and CNS) nicotinc effects Lacrimation Sweating Salivation
antidote for organophosphate poisoning
Atropine
MOA of atropine
Competitively blocks all muscarinic receptors only
No nicotinic effects
Antidote for organophosphate poisoning with A different MOA than atropine.
Describe the MOA
Pralidoxime
Binds phosphorous of organophosphate. Breaks organophosphate bond with cholinesterase
Pralidoxime must be administered before ____ hrs of organophosphate bond wity cholinesterase occurs
6-8 hrs
Atropine is found in what plant
Atropa belladonna
Define cycloplegia
Ciliary muscle paralysis
Competitively blocks all muscarinic receptors and restores balance to the basal ganglia. Which anti muscarinics are used in parkinson’s diesease?
Benztropine
Biperiden
Trihexyphenidyl
Park and Beep(BIP) your Tri logo Benz
Benztropine and similar drugs reduces what symptoms more than others in parkinsons?
Tremors
Why is ipratropium the preferred bronchodilator in patients with COPD and heart disease?
Least likely to cause tachycardia and arrhythmias
Scopolamine is a muscarinic antagonist used in
Motion sickness
What is the main action of scopolamine aside from anti muscarinic effects?
Antagonize histamine and serotonin
Usual route of intake of scopolamine
Transdermal patch
Atropine toxicity manifests as
Hot as a hare Dry as a bone Red as a beet Blind as a bat Mad as a hatter
Nicotinic antagonist used in HTN (obsolete)
Hexanethonium
Trimethaphan
Notable side effect of hexamethonium
Postural hypotension
MOA of hexamethonium
Competitively blocks Nn nicotinic ach receptors (ganglion blocker)
Treatment of open angle closure glaucoma with a long duration of action (1 week)
Echothiophate
Antidote for tubocurarine
Edrophonium
Depolarizing NM blocker
Succinylcholine
Non depolarizing NM blocker
Tubocurarine, pancuronium, atracurium, vecuronium
Primary neurotransmitter at the sympathetic postganglionic neuron
Norepinephrine
Exceptions to norepi as the transmitter in sympa postganglionic neuron effector cell synapse?
What is the transmitter used in these exceptions?
Eccrine sweat glands
Vasodilator sympa fibers in the skeletal muscle
Ach
Rate limiting step in the synthesis of NE
Hydroxylation of tyrosine
____ vasodilates renal blood vessels while ____ vasoconstricts
Dopamine
NE
The synthesis step of tyrosine to DOPa is inhibited by
Metyrosine
Transport to vesicle of dopamine is inhibited by which drug?
Reserpine
Release of NE or dopa is blocked by
Guanethedine and bretylium
Release of NE is promoted by which substances
Amphetamine
Tyramine
Reuptake of NE is blocked by
Cocaine and imipramine
Enzymes that metabolize NE
MAO
COMT
What final products are seen in the metabolism of NE
Metanephrines
VMA
2nd messenger of Alpha 1 receptors
IP3 DAG
D1 adrenergic effects
Dilates renal and other splanchnic vessels
Beta 3 adrenergic effects
Lipolysis of fat cells
d2 adrenergic effects
Inhibits adenylyl cyclase in nerve terminals
MOA of epi and norepi
Non selective alpha and beta agonist
Dopamine is an non selective sympathimimetic. What is its unique effect on D1 receptors?
Vasodilation in splanchnic and renal vessels
Dopamine varies its actions depending on dose. What are the dose dependent actions of dopamine. Enumerate the dose, receptor and effects.
LOW dose (1-5mcg/kg/min)
D1 receptors
Vasodilation in renal and splanchnic vessels
MED dose (5-15mcg/kg/min)
B1 receptors
Inc renal blood flow, heart rate, Cardiac output and contractility
HIGH dose (>15) Alpha receptors Vasoconstriction and inc blood pressure
Non selective beta adrenergic drug that is mainly used in asthma
Isoproterenol
Alpha 1 selective agonists
Phenylephrine
Pseudoephedrine
Main indication for phenylephrine
Decongestant
SE: rebound nasal congestion
Selective alpha 2 agonists
Clonidine
Methyldopa
Apraclonidine
Main alpha 2 agonist used in preeclampsia
Methyldopa
Notable side effect of methyldopa
Hemolytic anemia (positive coombs test)
Alpha 2 agonist used in hypertension. What is its side effect?
Clonidine
Reboudn htn
Antidote for rebound hypertension with clonidine
Phentolamine
Apraclonidine is an alpha 2-agonist used mainly in? What are similar drugs?
Glaucoma
Brimonidine
Beta 1 selective agonist
Dobutamine
Dobutamine is used in?
Acute heart failure, cardiogenic shock
Main side effects of dobutamine
Tachycardia
Arrhythmias
Tachyphylaxis
Cardiac testing in amputated patiens can be done using which drug?
Dobutamine
Beta 2 agonists
Salbutamol
Albuterol
Terbutaline
Ritodrine
2 main uses of beta 2 agonists
Asthma
Tocolysis in preterm labor (terbutaline and ritodrine)
Non selective alpha blockers
Phenoxybenzamine
Phentolamine
Irreversible blocker of alpha adrenergic receptors
Phenoxybenzamine
Drug of choice for presurgical pheochromocytoma
Phenoxybenzamine
Phentolamine
Reversible blocker of alpha adrenergic receptors
Phentolamine
Main use of phentolamine
Presurgical pheochromocytoma
Antidote to alpha 1 agonist overdose
Rebound htn
What is the pharmacologic advantage of alpha 1 selectivity?
Reflex tachycardia is less common and less severe
Propanolol is a
Non selective beta blocker
What do u watch out for in propanolol use?
Masks sx of hypoglycemia in diabetics
Beta blocker with the longest half life
Nadolol
Beta blocker with the shortest half life
Esmolol
Beta blockers used in pheochromocytoma and rationale for use
Labetalol and carvedilol
Combined alpha and beta blockade
Beta blockers with intrinsic sympathomimetic activity thus advantageous in patients with asthma
Acebutolol
Pindolol
Local anesthetic effects are seen in beta blockers except in ___ which makes them useful in treating glaucoma
Timolol
Betaxolol
Selective beta 1 blockers
Atenolol
Betaxolol
Esmolol
Acebutolol
Metoprolol
What beta 1 selective beta blocker is used in SVT
Esmolol
Alpha 2 agonist used in glaucoma
Apraclonidine
Prostaglandin used in glaucoma to increase outflow through the canal of schlemm
Latanoprost
Cholinomimetics used in glaucoma for ciliary muscle contraction thus opening the trabecular meshwork and inc outflow.
Pilocarpine
Physostigmine
