Pharmacological modulation of the ANS Flashcards
List each of the adrenoceptor-mediated responses
alpha-1 - Arterial narrowing, seminal vesical contraction, radial muscle contraction (wide pupils)
alpha-2 - Reduction of transmitter release from sympathetic nerves
Beta-1 - Increased heart rate and contraction force
Beta 2 - Airway and artery relaxation, bladder and uterus relaxation
Beta-3 - Sugar metabolism, bladder and uterus relaxation
List all the muscarinic cholinoceptor-mediated responses
M1 - Gut acid production and other secretions
M2 - Decreased cardiac activity
M3 - Saliva production, release of NO from endothelium, contraction of visceral smooth muscles, pupil narrowing
M4, M5 - CNS
Name the antagonists and agonists of the nicotinic acetylcholine receptor
Antagonist - Hexamethonium, tubocurare, pancuronium
Agonist - Nicotine lobeline
Name the antagonists and agonists of the muscarinic receptors
Antagonists - Atropine, hyoscine, pirenzepine (M1 only) and ipratropium
Agonist - Muscarine, bethanecol, pilocarpine
Describe and categorise cholinesterase inhibitors
Short acting: Edrophonium, tracrine, donepezil
Medium acting: Neostigmine, physostigmine, rivastigmine
Irreversible: Parathion, ectothiopate, dyflos
State some clinical uses of muscarinic blockers
Premedication before anaesthesia to reduce secretions, sedation (hyoscine), prevent vagal effects
In heart bock to increase AV conduction
Ophthalmology to produce mydriasis for examination
Bronchodilation in severe airways disease (ipratropium due to poor lipid solubility)
Anti-spasmodic in GI colic
Overactive bladder - Solifenacin
Antacid - pirenzepine - M1 selective
Treatment of antiChE poisoning
Motion sickness
State the clinical uses of cholinoceptor agonists
Pilocarpine (mAchR agonist) used to treat glaucoma and dry mouth.
Bethanecol (mAchR agonist) occasionally used to aid bladder / gastric emptying
Succinylcholine - High affinity for nAChR agonist used in surgery - depolarising paralysis
State the clinical uses of cholinesterase blockers
E.g. tacrine, donepezil or rivastigmine used in dementia and neuromuscular diseases e.g. myaesthesia gravis or eaton-lambert syndrome, raises the level of endogenous acetylcholine.
State clinical uses of nicotine blockers
Tubocurarine, pancuronium, vecuronium and atacurium act as muscle relaxtants by being direct nAchR blockers
Suxamethonium acts as a depolarising blocker by being a direct nAchR agonist
How are beta 1 blockers beneficial in relation to cardiovascular disease
By reducing heart rate, the demand of the heart will decrease while the supply increases as blood vessels are not constricted.
hh
Angiotensinogen -> Angiotensin 1 -> Angiotensin 2 -> Increased blood pressure due to artery constriction -> Cardiac remodelling
What does prazosin do
Alpha adrenoceptor blocker - Reduce arterial narrowing
What does phenoxybenzamine do
Helps against adrenal gland tumour and reduces hypertension
What are the symptoms of benign prostatic hyperplasia
Weak, slow urinary stream, hesitancy to urinate
Prolonged voiding
Dribbling at end of urination
Inability to empty bladder completely
Sometimes uncontrollable need to void
Night time urination
What is benign prostatic hyperplasia caused by
Enlarged prostate
