Pharmacology of Peripheral Neural Transmission Flashcards
Atropine
Non-selective mAChR antagonist - blocks PNS actions
Dilate eyes, decrease glandular secretions, bronchodilation, decreased GI motility, increased HR
Atracurium, Pancuronium
Non-depolarising N.M.J. blockers used as muscle relaxants in surgery (greater effect on fast muscle fibres)
Riociguat
Allosteric activator of soluble guanylyl cyclase used in some forms of pulmonary hypertension
Carbidopa
Peripheral DDC inhibitor used to reduce the side-effects of L-DOPA
Atenolol
Beta-1-receptor antagonist used as an antihypertensive
Tetanus toxin
Cleaves synaptobrevin in inhibitory neurons (to motor neurons) increasing excitability
L-DOPA
Dopamine precursor used to increase production in brain in Parkinson’s
Entacapone
COMT inhibitor used in Parkinson’s
Reserpine
Binds VMAT-2 preventing uptake of NA (& 5-HT) into vesicles was used as antihypertensive but discontinued due to profound depression
Hexamethonium
Ganglionic nAChR channel pore blocker
Isoprenaline
Beta-receptor agonist was used in asthma but the increase in HR was problematic
Mecamylamine
Non-competitive ganglionic blocker
Pirenzepine
M1 antagonist used to decrease acid secretion
Darifenacin
M3 antagonist used to decrease bladder activity
Dipyridamole
Blocks uptake of adenosine - potentiates response
& inhibits PDE-V
Tyramine
Displaces NA from vesicles causing vasoconstriction (especially in people taking MAO inhibitors)
Clonidine
Slightly selective alpha-2-receptor agonist used as an anti-hypertensive (acts in hindbrain - maybe on imidazoline I-1-receptor)
Edrophonium
Short-acting anti-AChE used to diagnose myasthenia gravis
Alpha-bungarotoxin
N.M.J. blocker
Clorgiline
Selective inhibitor of MAO-A used in depression
Xylazine
Alpha-2-receptor agonist veterinary sedative (good because doesn’t cause respiratory depression)
Phenoxybenzamine
Blocks uptake 2 (& 1 at 10x high concentrations) irreversible alpha-receptor blocker
Dobutamine
Beta-1-receptor agonist used in acute cardiogenic shock
Benzilylcholine mustard
Irreversible mAChR antagonist (alkylates the receptor)
Triethylcholine
Competitive substrate for choline acetyltransferase: forms false transmitter acetyl-TECh
Butaxamine
Beta-2-receptor antagonist
Beta-bungarotoxin
Binds potassium channel and has PLA2 activity - destroys the nerve ending
Neostigmine
Medium-acting anti-AChE used as oral treatment for myasthenia gravis
Sildenafil
PDE5 inhibitor used to treat impotence and pulmonary arterial hypertension
Phaeochromocytoma
Catecholamine-secreting chromaffin tumour causing hypertension
Prazosin used to reduce BP and atenolol/phenoxybenzamine used to prevent the effects of large catecholamine release when tumour removed surgically
Guanethidine
Block NA release
Pilocarpine, Bethanechol
Non-selective mAChR agonist (& muscarine)
P: used topically to treat glaucoma
B: used in urinary retention
Alpha-latrotoxin
Binds neurexins forming a calcium permeable pore causing mass ACh release
Amitryptiline, Imipramine
Tricyclic antidepressants block uptake 1
Trimetaphan
Autonomic ganglion blocker - competitive antagonist of nAChR
Phenylephrine
Alpha-1-receptor agonist used to increase BP in acute hypotension
Caffeine
A1-adenosine receptor antagonist it’s waking effect most prominent after prolonged wakefulness
Also inhibits PDE causing an increase in heart rate/force of contraction
Nitroglycerin
Nitrovasodilators (NO donor) used to treat angina
Cevimeline
M3 agonist (only selective mAChR agonist) used to treat dry mouth in Sjögren’s syndrome
d-tubocurarine
Relatively non-selective nAChR antagonist
Tranylcypromine
Non-selective irreversible MAO inhibitor used in refractory depression
Tripitramine
M2 antagonist
Pralidoxime
Reverses phosphorylation caused by Dyflos/Malathion but only in first few hours
Vesamicol
Non-competitive & reversible blocker of the vesicular ACh transporter
Dyflos, Malathion
Long-acting (irreversible) anti-AChE - organophosphorus compounds
Malathion used as insecticide (lice)
Sugammadex
Restores transmission blocked by steroid N.M.J. blockers by forming an inactive complex in plasma, excreted in urine
Botulinum toxins
Blocks transmission, preferentially affects cholinergic nerves:
B, D, F, G: cleave synaptobrevin
A, E: cleave SNAP-25
C1: cleaves syntaxin & SNAP-25
Salbutamol
Beta-2-receptor agonist used to relieve bronchoconstriction in asthma
Salmeterol is a long-acting agonist
ADMA
Endogenous NOS inhibitor
Alpha-methyltyrosine
Competitive inhibitor of TOH used experimentally to decrease NA production
Labetalol
Combined alpha/beta-receptor antagonists used to treat hypertension in pregnancy
Dexamfetamine
Taken up into vesicle, reduces pH gradient and therefore amine storage
Ritalin & MDMA similar
Propranolol
Beta-receptor antagonist was used as an antihypertensive but there is a risk of bronchoconstriction, also causes fatigue & claudication
Tamsulosin
Alpha-1A-receptor antagonist used to allow bladder emptying in benign prostatic hyperplasia
Dutasteride used a co-therapy to inhibit testosterone production
Phentolamine
Alpha-receptor antagonist used in hypertension until superseded by selective drugs (non-selective give reflex tachycardia)
Idazoxan
Alpha-2-receptor antagonist
Hemicholinium
Binds to the choline transporter inhibiting uptake
Cocaine
Blocks uptake 1
Selegiline
Selective inhibitor of MAO-B used in Parkinson’s
Alpha-methyldopa
Converted to alpha-methylNA which causes vasodilation
Decamethonium, Suxamethonium
N.M.J. depolarising blocker
Prazosin
Alpha-1-receptor antagonist used to treat hypertension and Raynaud’s syndrome (peripheral vascular disease)
Mirabegron
Beta-3-receptor agonist used to treat overactive bladder