Autonomics Flashcards
Choline transport across plasma membrane blocked by? Inhibiting acetylcholine formation by ChAT
Hemicholinium
Block rate limiting step
Immune mediated degradation of voltage gated calcium channels?
Lambert Eaton
Inhibit active transport of ACh into vesicles for storage?
Vesamicol - “VESicle”
Alter synaptobrevins to prevent release of ACh into junction?
Botulinum toxin
Indirect acting cholinomimetics that inhibit acetylcholinesterase, prevent ACh degradation?
Carbamate
Organophosphate
Direct acting muscarinic cholinomimetic for post op bowel and bladder atony?
Betanechol
MOA: Activates M3. Bladder wall contraction, sphincter relaxation
Betanechol AE?
Cyclospasm. Diarrhea. Reflex tachycardia. Sweating.
Direct acting muscarinic cholinomimetic for glaucoma, sjogren and sicca?
Pilocarpine
MOA: Activate M3. Inc aqueous humor outflow, inc salivation.
Sjogren characterized by?
Xerostomia. Xerophthalmia. Rheumatoid arthritis.
Sicca: dry mouth, dry eyes only
Pilocarpine AE?
Cyclospasm - manifest as BOV
Miosis (excessive M3 action)
Direct acting nicotinic cholinomimetic used for smoking cessation?
Nicotine
MOA: Activate Nn and Nm
May cause mushroom poisoning?
Amanita muscaria
Nausea vomiting diarrhea
Toxicity of nicotine?
Paralysis (blocks depolarization of motor end plate)
MOA of indirect acting cholinomimetics?
Inhibit breakdown of ACh by acetylcholinerase. Enhance ACh action where it is normally secreted
indirect acting cholinomimetic used to DIAGNOSE myasthenia gravis?
Edrophonium given IV
aka Tensilon Test
Differentiate myasthenic crisis from cholinergic crisis by edrophonium
MC - improve after giving drug (Infection, stress, UNDERmedication)
CC - worsen (OVERmedication)
“MUCOr”
Autoimmune destruction of nicotinic ACh receptors - proximal muscle weakness, ocular and bulbar symptoms
Myasthenia gravis
indirect acting cholinomimetic for the TREATMENT of MG? Also for ogilvie (acute colonic pseudoobstruction)
Neostigmine
Neostigmine side effects may be blocked by?
Atropine
Cholinergic antag
indirect acting cholinomimetic used for treatment of alzheimer’s?
Rivastigmine
Signs and symptoms of organophosphate poisoning?
DUMBBELSS (wet patient)
Diarrhea. Urination. Miosis. Bronchospasm. Bradycard. Excitation of CNS. Lacrimation. Salivation. Sweating.
Antidote for organophos poisoning?
First choice: Atropine (muscarinic blocker)
Alt: Pralidoxime (regenerate more cholinesterase)
Golden period for giving pralidoxime?
6-8 hours
Before aging of organophosphate bond with cholinesterase
Muscarinic cholinergic antagonist for parkinson’s?
TRAP Tremors. Rigidity. Akinesia. Postural changes.
Benztropine
PARK your BENZ
Most effective vs Tremors
Muscarinic cholinergic antagonist for asthma and COPD?
Ipratropium
Prevent bronchoconstriction!!
Less tachycardia and arrhythmia
Muscarinic cholinergic antagonist for motion sickness?
Scopolamine - as TD patch
Atropine toxicity?
Hot as a hare - hyperthermia Dry as a bone - Dec secretions Red as a beet - flushing, due to cutaneous vasodilation Blind as a bat - BOV Mad as a hatter - CNS tox
Contraindications for cholinergic blockers?
Infants - thermoreg still immature
Acute angle closure glaucoma - dec outflow of aqueous humor, worsen iop
BPH - worsen urinary retention
Nicotinic cholinergic antagonist used for hypertension but is now obsolete? Due to what AE?
Hexamethonium
AE: Massive postural hypotension
Example of depolarizing neuromuscular blocker?
Used intraop to produce complete skeletal muscle relaxation.
Succinylcholine
Deposit - Success
Sympathetic postganglionic use NE except:
Eccrine sweat glands - M, ACh
Skeletal muscle VD - M3, ACh
Blocks tyrosine hydroxylase, block formation of L-Dopa from tyrosine?
Metyrosine
Storage of norepi into vesicles blocked by?
Reserpine
Inhibit release of NE by blocking VAMP and SNAP?
What enhances release of NE?
Guanethidine inhibits
Amphetamines enhance
Inhibit diffusion and reuptake of NE from synaptic cleft?
Cocaine - prolong NE action in cleft
TCA
Metabolites of epi and NE?
Epi - metanephrines
NE - VMA
Urine markers of pheochromocytoma
Non selective, direct acting sympathomimetic for cardiac arrest, anaphylaxis and asthma?
Epinephrine
Inc BP, inc HR, bronchodilate
Non selective, direct acting sympathomimetic for neurogenic and cardiogenic shock?
Norepinephrine
Non selective, direct acting sympathomimetic with renal vessel action for heart failure and shock?
Dopamine
Dose dependent action of dopamine
Low dose 1-5: VD renal and splanchnic - D1 receptors
Mid dose 5-15: Inc HR, CO, RBF - Beta receptors
High dose >15: systemic VC - Alpha receptors
Alpha 1 selective sympathomimetic used as decongestant and mydriatic?
Phenylephrine
Causes mydriasis WITHOUT cycloplegia
Phenylephrine AE?
Rebound nasal congestion
Hypertension, stroke, MI
Alpha 2 selective sympathomimetic for hypertension? Taken sublingually
Clonidine
AE: Dry mouth
Significant AE of clonidine if not tapered?
Rebound HPN
Antidote: Phentolamine (nonselective alpha blocker)
Alpha 2 selective sympathomimetic used for preeclampsia?
Methyldopa
Methyldopa AE?
Hemolytic anemia
Positive coombs test
Alpha 2 selective sympathomimetic for glaucoma?
Apraclonidine
Dec aqueous humor secretion
AE: Dry eyes, BOV
Beta 1 selective sympathomimetic for acute HF and cardiogenic shock?
Dobutamine
Beta 2 selective sympathomimetic for asthma attacks and tocolysis of preterm labor?
Salbutamol
Contraindications for salbutamol?
COPD and heart disease
May precipitate arrhythmias
IRREVERSIBLE nonselective alpha adrenergic blocker for preop pheochromocytoma?
Phenoxybenzamine
Phenoxybenzamine AE?
Orthostatic hypotension plus reflex tachycardia
REVERSIBLE nonselective alpha blocker used as antidote for rebound hypertension caused by clonidine?
Phentolamine
Alpha 1 selective adrenergic antagonist for BPH and hypertension?
Prazosin
Prazosin AE?
First dose orthostatic hypotension
(Give low dose, taken at night)
LESS reflex tachy compared to nonselective alpha (phenoxyben and phentol)
Beta nonselective adrenergic antagonist for angina, hypertension, arrhythmia, hyperthyroidism?
Propanolol
Beta nonselective adrenergic antagonist with combined ALPHA AND BETA blockade for pheochromocytoma?
Labetalol
L-A-BETA-lol
Effect of beta nonselective adrenergic antagonist in diabetics?
Mask hypoglycemia symptoms
Tachycardia, tremors, anxiety
Used for angina and hypertension in patients with asthma? Due to this property.
Pindolol. Acebutolol.
Due to ISA Intrinsic sympa activity
Less bronchospasm!
Beta blocker with shortest half life? Longest?
Shortest - Esmolol (Small)
Longest - Nadolol (Nasa dolo)
Beta 1 selective adrenergic antagonist for angina, hpn, SUPRAVENTRICULAR TACHYCARDIA?
Atenolol
Esmolol