Pharmacology Of Peripheral Nerve Transmission

Front 1

Methacholine

Back 1

ACh analogue, slowly hydrolysed by AChE

Front 2

Carbachol

Back 2

Analogue of ACh, resistant to AChE Used to treat glaucoma

Front 3

Bethanechol

Back 3

Analogue of ACh, resistant to AChE. Used to treat postop urinary retention, postop paralystic ileus, Xerostomia

Front 4

Pilocarpine

Back 4

Naturally occuring cholinomimetic alkyloid, from Pilocarpus jaborandi. Used to treat Glaucoma, Xerostima, and produce miosis

Front 5

Muscarine

Back 5

Naturally occuring cholinomimetic alkyloid, from Amantia muscarina.

Front 6

Arecholine

Back 6

Naturally occuring cholinomimetic alkyloid, from Betel nuts.

Front 7

Atropine

Back 7

Naturally occuring competitive reversible muscarinic receptor antagonist from Atropa belladonna. Blocks PSN. Used as antidote to block PSN stim, to produce mydriasis for eye examination or cosmetic. Emergency treatment of AChE inhibitor toxicity, emergency severe brachycardia, emergency asthma attacks when not responsive to B adrenergic agonists, peptic ulcers

Front 8

Tetanus toxin

Back 8

Cleaves synaptobrevin, preventing vesicle fusion. Used to relax muscles, reduce pain and severe underarm swelling.

Front 9

Botulinum toxins B,D,F,G

Back 9

Cleaves synaptobrevin, preventing vesicle fusion. Used to relax muscles, reduce pain and severe underarm swelling.

Front 10

Botulinum toxins A,E

Back 10

Cleaves SNAP-25, preventing vesicle fusion. Used to relax muscles, reduce pain and severe underarm swelling.

Front 11

Botulinum toxin C1

Back 11

Cleaves SNAP-25 and syntaxin, preventing vesicle fusion and ACh release. Used to relax muscles, reduce pain and severe underarm swelling.

Front 12

Alpha-latrotoxin

Back 12

Black widow spider poison, explosively stimulates Ca2+ dependent ACh release

Front 13

Physostigmine

Back 13

From the calabar bean. Reversible AChE inhibitor. Reduce amount of ACh hydrolysed at NMJ and some direct actication. Tertiary amine, therefore CNS signs. Moderatly lipid soluble. Causes miosis, antagonises atropine and curare. Used to treat glaucoma, could be used for myasthenia gravis

Front 14

Neostigmine

Back 14

Reversible AChE inhibitor. Reduce amount of ACh hydrolysed at NMJ and some direct actication. Quaternary amine, poor lipid solubility. More selective action at nicotinic muscular receptors than MRs. Restore strength in myasthenia gravis patients. Used to treat paralyic ileus and and urinary bladder atony.

Front 15

Edrophonium

Back 15

Reversible AChE inhibitor. Quaternary amine, very short acting, doesn't form covalent bond with AChE. Used in diagnosis of myesthenia gravis. Also used to establis doses of other AChE inhibitors

Front 16

Isoflurophate (DFP)

Back 16

Irreversible AChE inhibitor. Prototypical organophosphate. Lipid soluble, enters CNS.

Front 17

Malathion

Back 17

Irreversible AChE inhibitor. Used as an insecticide, must be metabolised to become active.

Front 18

Parathion

Back 18

Irreversible AChE inhibitor. Used as an insecticide, must be metabolised to become active.

Front 19

Sarin gas

Back 19

Irreversible AChE inhibitor. Used as a nerve gas. Volatile

Front 20

Pralidoxime

Back 20

Antidote to irreversible AChE inhibitor. Splits phosphodiester bond. Not well absorbed from GI tract, does not penetrate CNS - to be used in conjunction with atropine

Front 21

Scopolamine

Back 21

Muscarinic receptor antagonist. Tertiary amine. Found in Hycoscymas niger (henbane). Similar actions to atropine, but actions on CNS more important. Used to prevent motion sickness, preanaesthetic meds when parasympathomimetics involved, eye exams, peptic ulcers, Parkinson's

Front 22

Nicotine

Back 22

Ganglionic stimulant at autonomic ganglia, nicotinic receptors causing depolarisation. Larger doses, depolarisation is followed by depolarisation blockade. Stimulation followed by depression, stimulain of mesolimbic reward pressure, increased heart rate and blood pressure.

Front 23

Hexamethonium

Back 23

Ganglion blocking agent, blocks nicotinic receptors at autonomic ganglia. Effecs dependent on target organ

Front 24

Mecamylamine

Back 24

Ganglion blocker, only one still available today

Front 25

Curare

Back 25

Non depolarising, competitive blacker at NMJ, prevents ACh from binding. Paralyses white fibres more than red. Does not prevent release of ACh, can be competed away. diminished epps. not absorbed through GI tract, not cross BBB. Not metabolised, excreted by kidney. Used to relax muscles under anaesthesia

Front 26

Atracurium

Back 26

Compared to curare, faster onset, shorter duration and fewer side effects. Eliminated via spontaneous hydrolysis and plasma cholinesterases. Used to relax muscles under anaesthesia

Front 27

Succinylcholine

Back 27

Depolarising blocking agent. Interacts with nicotinic receptors at NMJ causing transient burts of APs, followed by inactivation. Short duration, hydrolysed by plasma cholinesterases. Used to relax muscles under anaesthesia

Front 28

Alpha-methyltyrosine

Back 28

Inhibits tyrosine hydroxylase -- blocks synthesis of NA.
Treatment of phenochromacytomas that make too much NA

Front 29

Carbidopa

Back 29

Inhibits DOPA carboxylase. Used to treat Parkinson's along with L-dopa to reduce peripheral side effects

Front 30

Methyldopa

Back 30

Metabolised into alpha-methylnoradrenaline - false transmitter. Stored and released in vesicles.
alpha1 less vasoconstriction
a2 presynaptic, greater effect inhibits neurotransmitter realease.
Antihypertensive.

Front 31

Disulfiram

Back 31

Inhibits dopamine beta hydroxylase and causes a partial depletion of NA stores

Front 32

Reserpine

Back 32

Alkaloid from Rauwolfia shrub. Binds tightly to catecholamine recognition site on storage vesicles. Blocks accumualtion of catecholamines by synaptic vesicles and therefore depletion by MAO. Used as an antihypertensive, but causes depression.

Front 33

Tricyclic depressants (imipramine)
Cocaine

Back 33

Inhibit uptake 1. Accumulation of NA at receptors and enhance sympathetic nerve activity. Also in CNS inhibit 5-HT uptake

Front 34

Phenoxylbenzamine

Back 34

Inhibit uptake 1
Alpha antagonist
-used for treating phaechromacytomas to block hypertensive effects

Front 35

Entacapone

Back 35

COMT inhibitor. Used to treat Parkinson's.

Front 36

Clorgyline

Back 36

MAO-A inhibitor.
Used to treat depression

Front 37

Selegine

Back 37

MAO-B inhibitor
Used to treat Parkinson's - potentiates remaining dopamine in substantia nigra.

Front 38

Tranylcypromine
Iproniazid

Back 38

Nonspecific inhibitors of MAO, increases cytoplasmic concentration of catecholamines so more leak out into the nerve terminal

Front 39

Amphetamine
Tyramine
Ephedrine

Back 39

Indirectly acting sympathomimetic agents. Uptake 1 then displace NA from vesicles. Have postsynaptic effects;
Ephedrine used as nasal decongestant, relieves bronchospasm by B2 effect

Front 40

Guanethidine

Back 40

Uptake 1, competes with NA. potentiates effects of exogenous catecholamines. Some NA leaks out and causes postynaptic stimulation intially. At low chronic doses, depletes NA stores and blocks neurones. In large doses causes inhibition of exocytosis. Was used as antihypertensives (also Bretylium)

Front 41

Isoprenaline

Back 41

Aderinergic beta1&2-agonist.
Was used to treat asthma as reduces bronchospasm.
Side effects tachycardia

Front 42

Salbutamol

Back 42

Aderinergic beta2-agonist.
Used to treat asthma (aerosol)
and premature uterine contractions

Front 43

Dobutamine

Back 43

Aderinergic beta1-agonist.
Given iv to give postitive ionotropic effect during cardiac shock. Also some use as heart block

Front 44

Noradrenaline

Back 44

Aderinergic beta1&alpha1-agonist.
IV pressor to raise blood pressure in shock or blood loss to allow perfusion of vital organs. No B2 effects, therefore better presser than Adr, even though lower A1 effects.

Front 45

Adrenaline

Back 45

Mixed aderinergic agonist.
Used in emergency situations:
-cardiac stimulant
-bronchodilator
-anaphylaxis(reverse vasodilation and bronchoconstriction)

Front 46

Phenylephidrine

Back 46

Aderinergic alpha1-agonist.
-local use for nasal congestion (vasoconstriction)
-causes hypertension and reflex brachycardia

Front 47

Clonidine

Back 47

Aderinergic alpha2-partial agonist.
-antihypertensive, lowers central sympathetic outflow
-introduce gradually and withdraw slowly
-help to treat opiate withdrawal

Front 48

Yohimbine

Back 48

Alpha adrenergic antagonist
not used therapeutically

Front 49

Prazosin

Back 49

Alpha adrenergic antagonist
Causes vasodilatation and relaxation of muscles in bladder neck (urinary retention)

Front 50

Phentolamine

Back 50

Alpha adrenergic antagonist. Some use in Raynaud's syndrome and peripheral vascular disease. Also to treat phaenochromocytoma

Front 51

Propranalol

Back 51

Beta adrenergic antagonist. Was used to treat hypertension, but side effects e.g. bronchoconstriciton

Front 52

Atenolol
Practolol

Back 52

Beta-1 adrenergic antagonists. Reduces effect of exercise on heart rate and arterial pressure

Front 53

Caffeine

Back 53

A1 receptor antagonist
increases wakefulness in CNS areas. Most prominent after prolonged wakefulness

Front 54

Sildenafil

Back 54

Inhibitor of type 5 phosphodiesterase. Stops degradation od cGMP to maintain contraction in smooth muscle cell. Viagra

Front 55

L-NMMA (N MonoMethyl Arginine)
L-NAME (Nitro Arginine Methyl Ester)
L-NOARG (NitrO ARGine)

Back 55

Inhibit NOS, analogues of L-arginine
D form inactive