Pharmacology Of Peripheral Neural Transmission Flashcards
Alpha- latrotoxin
Spider venom. Acts presynaptically - binds to neurexins (transmembrane proteins on plasma membrane of nerve) to cause the release of neurotransmitters (eg. ACh) via the formation of Ca2+ permeable channels.
AMDA (asymmetric dimethyl arginine)
Interfere with L-arginine in the production of NO. Less vasodilatation. High levels associated with cardiovascular diseases. Lowering levels may have important therapeutic effects.
Alpha-methyl dopa
Acts as a false transmitter in the place of NA. Acts as an Alpha-2 adrenergic agonist. Less vasoconstriction. Antihypertensive (mainly CNS).
Amitriptyline
Serotonin-noradrenaline uptake (1) inhibitor. Tricyclics antidepressant.
Atenolol
Beta-1 receptor antagonist. Negative inotropic and chronotropic effect. Treat hypertension, long QT, myocardial infarction.
Atracurium
Competitive antagonist of nAChR at NMJ. Block end plate potential and tetanic fade occurs. Skeletal muscle relaxant in anaesthesia.
Atropine
Competitive antagonist of mAChR. Parasympatholytic.
Bethanechol
Selectively stimulates mAChR without nicotinic. Not selective for subtypes. Parasympathomimetic. Used in bladder dysfunction to stimulate contraction.
Botulinum toxin
Binds to SNARE proteins (synaptobrevin, SNAP-25, syntaxin) preferentially on cholingeric neurons. Interfers with release of ACh. Used for excessive sweating, cosmetic, cervical dystonia.
Beta- bungarotoxin
Blocks ACh release. Acts through phospholipase A2 and localised to membrane through K+ channel bonding moiety. Causes nerve destruction.
Butaxamine
Beta (1) and 2 antagonist. No clinical use.
Caffeine
Adenosine 1 receptor antagonist. Relieves drowsiness temporarily. Also inhibits PDE so has +ve chronotropic and inotropic effects. Vasodilator. Diuretic.
Clonidine
Slightly selective for alpha 2 adrenergic receptors. Inhibition of SNS output. Antihypertensive.
Clorgiline
Selective inhibitor of MAO-A. Prevents degradation of neurotransmitters. Used in depression.
Cocaine
Blocks NET uptake 1 transporter.
D-amphetamine
Weak inhibitor of MAO. Taken up into vesicle, reduces pH and packaging of amines. Displaced NA leaves nerve ending. Treat ADHD.
Darifenacin
mAChR3 antagonist. Decreases bladder contraction. Treat incontinence.
Dipyridamole
Blocks adenosine transport back into cells so potentiates responses mediated by adenosine.
Dobutamine
Selective B1 agonist. Sympathomimetic. Used in heart failure and acute cardiogenic shock.
D-tubocurarine
nAChR antagonist. Not selective for NMJ/ganglion. Skeletal muscle relaxant.
Dyflos
Irreversible anti-cholinesterase. Parasympathomimetic. Used to treat glaucoma.
Edrophonium
Reversible inhibitor of AChE at NMJ. Diagnose myasthenia gravis.
Guanethidine
Enters nerve by uptake 1, compete with NA. False transmitter. Block release of NA.
Hemicholinium
Blocks the transporter by which choline is taken up into the nerve. Limits ACh production.
Hexamethonium.
Use dependent blockade of ganglionic transmission - block of open channel. Used for hypertension. Discontinued due to side effects - loss of para/sympathetic control.
Idazoxan
Selective A2 antagonist. Possible use as antidepressant/schizophrenia.
Imipramine
Tricyclic antidepressant. Blocks NET (uptake 1). Increased catecholamine levels.
Isoprenaline
Non-selective beta agonist. Used in bradycardia, heart block and asthma (old).
Labetalol
Alpha1/beta antagonist. Used in pregnancy induced hypertension
Malathion
Long acting, irreversible anticholinesterase. Insecticide to kill lice - paralyse without damaging host.
Mecamylamine
Nonselective, noncompetitive antagonist of mAChR. Antihypertensive and anti-addictive drug to stop smoking.
Muscarine
From mushroom. Nonselective agonist of mAChR.
Neostigmine
Short acting inhibitor of ACherase. Improve muscle tone in myasthenia gravis patients and reverse muscle relaxants.
Nicotine
Agonist at the ganglionic nAChR, opens ion channel. Long stimulation causes inactivation of VG Na+ channels (phase I block) - depolarising block.
Nitroglycerin
Nitric oxide donor. Vasodilatation and relaxation of smooth muscle. Angina.
Pancuronium
Competitive antagonist at nAChR at NMJ. Used in anaesthesia to produce muscle relaxation (fast more than slow).
Phentolamine
Reversible non selective alpha adrenergic antagonist. Vasodilatation but cause reflex tachycardia and postural hypotension.
Phenylephrine
Selective a1 agonist. Raise blood pressure in acute hypotension. Decongestant and dilated pupils.
Pilocarpine
Nonselective muscarinic receptor agonist. Parasympathomimetic. Glaucoma and dry mouth.
Pralidoxime
Binds to acetylcholinesterase to relieve poisoning from organophosphates. Reverses paralysis of respiratory muscles.
Prazosin
A1 receptor antagonist. Treat hypertension and anxiety.
Propranolol
Non selective beta blocker. Hypertension, anxiety and panic.
Reserpine
Depleted catecholamines from peripheral sympathetic nerve endings by irreversibly blocking VMAT. Neurotransmitters cannot be transported into vesicles.
Salbutamol
Selective B2 antagonist. Relief of bronchospasm on asthma and COPD.
Selegiline
MAO-B irreversible inhibitor. Parkinson’s, depression and dementia.
Sildenafil
Viagra. Inhibits PDE5, reduces degradation of cGMP. Erectile dysfunction and pulmonary arterial hypertension.
Suxamethonium
Selective for nAChR at NMJ. Block transmission by causing prolonged depolarisation.
Tetanus toxin
Binds to synaptobrevin. Retrogradely transported back to cell body and then to an inhibitory interneuron - unable to release transmitter so motor neurone more excitable.
Tranylcypromine
Non selective, irreversible MAO inhibitor. Treatment of refractory depression.
Tyramine
Indirectly acting sympathomimetic amine. Transported into nerve ending, displaces NA from vesicles and it is released. Only peripherally.
Xylazine
A2 agonist. Used for anaesthesia and analgesia in animals.
